Escherichia coli

J Bacteriol, 1980 Aug, 143(2), 971 - 80
In vitro gene fusions that join an enzymatically active beta-galactosidase segment to amino-terminal fragments of exogenous proteins: Escherichia coli plasmid vectors for the detection and cloning of translational initiation signals; Casadaban MJ et al.; We report the construction and use of a series of plasmid vectors suitable for the detection and cloning of translational control signals and 5' coding sequences of exogenously derived genes . In these plasmids, the first eight codons of the amino-terminal end of the lactose operon beta-galactosidase gene, lacZ, were removed, and unique BamHI, EcoRI, and SmaI (XmaI) endonuclease cleavage sites were incorporated adjacent to the eighth codon of lacZ . Introduction of deoxyribonucleic acid fragments containing appropriate regulatory signals and 5' coding sequences into such lac fusion plasmids led to the production of hybrid proteins consisting of the carboxyl-terminal segment of a beta-galactosidase remnant plus a peptide fragment that contained the amino-terminal amino acids encoded by the exogenous deoxyribonucleic acid sequence . These hybrid peptides retained beta-galactosidase enzymatic activity and yielded a Lac+ phenotype . Such hybrid proteins are useful for purifying peptide sequences encoded by exogenous deoxyribonucleic acid fragments and for studies relating the structure and function of specific peptide segments.

J Bacteriol, 1980 Aug, 143(2), 914 - 20
Patterns of polarity in the Escherichia coli car AB gene cluster; Gigot D et al.; The direction of transcription of the carAB gene cluster, which codes for Escherichia coli carbamoylphosphate synthase, was deduced from the effects of phage Mu-1 insertions in each of the two genes and from the results of ribonucleic acid-deoxyribonucleic acid hybridization experiments relating the quantity of car messenger ribonucleic acid to the location of various car mutations . The car locus appears to constitute an operon polarized from carA to carB . The levels of carA and carB products were determined in a large number of car mutants by using in vitro and in vivo complementation assays . The results obtained display strong anomalies, which are discussed in light of the conclusions described above.

J Bacteriol, 1980 Aug, 143(2), 1077 - 80
Deletion of a ribosomal ribonucleic acid operon in Escherichia coli; Ellwood M et al.; One (rrnE) of the seven operons which codes for ribosomal ribonucleic acid in Escherichia coli was deleted . No significant change in phenotype was observed even under maximum laboratory growth conditions.

Genetics, 1980 Aug, 95(4), 785 - 95
Translational coupling during expression of the tryptophan operon of Escherichia coli; Oppenheim DS et al.; E . coli trpE polar mutations are 10 time more polar on trpD gene expression than on downstream (trpC, B, or A) gene expression . This effects was shown to be the result of "translational coupling," in which efficient translation of trpE-trpD intercistronic punctuation region consists of overlapping stop and start codons, and the trpE and trpD gene products form a functional complex in the cell . In light observations and characteristics, several models for the mechanism of translational coupling are considered.

Appl Environ Microbiol, 1980 Aug, 40(2), 358 - 64
Heat damage to the chromosome of Escherichia coli K-12; Pellon JR et al.; The folded chromosome or nucleoid of Escherichia coli was analyzed by low-speed sedimentation in neutral sucrose gradients after in vivo heat treatment . Heat treatment of cultures at 50 degree C for 15, 30, and 60 min resulted in in vivo association of the nucleoids with cellular protein . Structural changes, determined by the increase in speed dependence of the nucleoids from heated cells, also occurred . These changes were most likely due to the unfolding of the typical compact nucleoid structure . The nucleoids from heated cells also had notably higher sedimentation coefficients (3,000 to 4,500S) than nucleoids from control cells (1,800S) . These nucleoids did not contain greater than normal amounts of membrane phospholipids or ribonucleic acid . We propose that the protein associated with the nucleoids from heated cells causes the observed sedimentation coefficient increases.

Mutat Res, 1980 Aug, 72(1), 43 - 7
N4-hydroxycytidine: a mutagen specific for AT to GC transitions; Janion C et al.; N4-Hydroxycytidine is a mutagen of the base-analog type and one of the products formed by treatment of cytidine with hydroxylamine . In this communication evidence is presented showing that, in contrast with other known base analogs, N4-hydroxycytidine results mainly, if not exclusively, in AT leads to GC transitional alterations in Escherichia coli K12.

Infect Immun, 1980 Aug, 29(2), 824 - 6
Immunization of suckling pigs against enterotoxigenic Escherichia coli-induced diarrheal disease by vaccinating dams with purified K99 or 987P pili: antibody production in response to vaccination; Isaacson RE et al.; Pilus-specific antibody levels measured by enzyme-linked immunosorbent assays in serum and colostrum of pregnant swine (dams) were shown to increase after parenteral vaccination with pili . Pilus-specific antibody levels in dams were correlated with protection of their suckling offspring against fatal diarrhea caused by enterotoxigenic Escherichia coli possessing the same pilus as the vaccine.

Infect Immun, 1980 Aug, 29(2), 685 - 91
Characterization of pili associated with Escherichia coli O18ac; Wevers P et al.; A strain of Escherichia coli O18ac isolated from the stool sample of a patient with diarrhea was found to agglutinate human erythrocytes . From the results presented it is suggested that this hemagglutination is mediated by pili . Isolated pilus preparations agglutinated human erythrocytes, whereas pilus-negative mutants did not . The serological and chemical analyses indicate that the pili associated with E . coli O18ac are distinct from other types found with E . coli.

J Infect Dis, 1980 Aug, 142(2), 220 - 8
Activation of intestinal guanylate cyclase by heat-stable enterotoxin of Escherichia coli: studies of tissue specificity, potential receptors, and intermediates; Guerrant RL et al.; Heat-stable enterotoxin (ST) of Escherichia coli increased guanylate cyclase activity in homogenates of rat and rabbit intestinal mucosa and stimulated intestinal fluid secretion in suckling mice . The ST effect on guanylate cyclase was dose-dependent, occurred without a time lag, and was confined to the particulate fraction . ST activation of guanylate cyclase was tissue-specific; ST did not alter activity of soluble or particulate rat liver, lung, heart, kidney, or cerebral cortex enzyme . The ST activity on guanylate cyclase and secretion was methanol-soluble and alkali-labile, and its effects were not altered by phentolamine, propranolol, or atropine . Monosialoganglioside did not reduce ST-induced secretion . However, indomethacin and butylated hydroxyanisole decreased the ST effect on both guanylate cyclase and secretion . Fluid secretion with ST sppears to result from specific activation of particulate intestinal guanylate cyclase . While adrenergic and cholinergic events are probably not involved in this process, the effects of ST may be mediated through prostaglandin synthesis or oxidative mechnanisms.

Eur J Biochem, 1980 Aug, 109(1), 285 - 90
Recovery of pure ribosomal proteins from stained gels . A fast method of purification of active proteins; Bernabeu C et al.; A simple technique has been developed for eluting ribosomal proteins from stained gels in the presence of an acetic acid solution . The ribosomal proteins are then separated from the dye by anion-exchange chromatography under dissociating conditions . Ribosomal proteins purified by these methods give total cross-reaction with proteins obtained by standard procedures, when tested by immunodiffusion against their corresponding antibodies, and show the same electrophoretic mobility as standard proteins in bidimensional polyacrylamide gel systems . Ribosomal proteins L7/L12, recovered from stained gels and purified by these methods, are able to reconstitute the elongation-factor-G-dependent GTPase activity of ribosomal particles deprived of these proteins . Radioactive protein L1, recovered in the same way, is incorporated into a total reconstituted 50-S subunit, competing with an excess of standard L1 present in the pool of total proteins from 50-S subunits used for reconstitution . These results suggest that bidimensional electrophoresis can be considered an alternative system of purification of active proteins from complex mixtures.

Mol Biol Rep, 1980 Jul 31, 6(2), 111 - 3
Polypeptide synthesis catalyzed by p-hydroxymercuribenzoate-modified ribosomes; Lopez-Rivas A et al.; The stimulation of poly(U)-directed polyphenylalanine synthesis produced by modification of Escherichia coli ribosomes with p-hydroxymercuribenzoate, at low molar ratios of reagent to ribosomes, is due to an increase in the average chain length of polyphenylalanine synthesized, and not to the activation of inactive ribosomes . At a higher molar ratio of p-hydroxymercuribenzoate to ribosomes, which produces no overall change in activity, approximately 50% of the active ribosomes present in the untreated preparation have been completely inactivated, and the remaining active ones, like the ribosomes of the stimulated preparation, synthesize polyphenylalanine at an increased rate as compared with the untreated ribosomes.

Mol Biol Rep, 1980 Jul 31, 6(2), 73 - 7
Noncoordinate control of the synthesis of different species of RNA in Escherichia coli K12 during uridine starvation; Bhattacharya S et al.; During uridine starvation in Escherichia coli K12, the rate of RNA accumulation comes down to about 7% of the nonstarved rate . This is achieved, in part, by an eight-fold increase in the assembly time of stable RNA molecules . However, the assembly time of mRNA molecules is not enhanced as much, being longer by a factor of 3 in starved cells compared to nonstarved ones . It, therefore, appears that the rate of synthesis of these two RNA species is noncoordinately controlled during uridine starvation . This control does not seem to be mediated by guanosine tetraphosphate.

Mol Biol Rep, 1980 Jul 31, 6(2), 89 - 94
Poly(A)-mRNA deprimerones in rat liver and Novikoff hepatoma cells; Hiliar M et al.; The poly (A)-mRNA fraction isolated by chloroform deproteinization of liver polysomes and poly(U)-Sepharose chromatography contains a low molecular weights (congruent to 1000) peptidic fraction . The peptides which we suggested to call deprimerones (1) were extracted with 80% ethanol at pH 9.5; after ethanol evaporation, they were purified on Sephadex G-25 column as a fraction of mol . wt . between 1600 and 600, yielding about 9 mg/mg mRNA . If deproteinization is performed with phenol-chloroform the yield is about 2 mg/mg mRNA . In Novikoff hepatoma the yield of the same preparation is only 2.7 mg/mg mRNA (about 70% decrease) . The obtained deprimerones are active in inhibiting transcription of thymus DNA with E . coli RNA polymerase and {3H}-GTP by about 90% at a ratio peptide/DNA = 2 . For comparison the deprimerones obtained previously (2) by extraction of deproteinized DNA inhibit transcription only by about 50% at the same peptide/DNA ratio . The results demonstrated a decrease of the poly (A)-mRNA deprimerone level during carcinogenesis and further support the previously demonstrated specific occurrence of deprimerones with poly(A)-mRNA . They remain in accordance with and provide further support for the deprimerone theory of carcinogenesis postulated earlier (1).

Biochim Biophys Acta, 1980 Jul 29, 608(2), 243 - 58
Internucleotide protein linkers in Ehrlich ascites cell DNA; Werner D et al.; DNA from Ehrlich ascites tumor cells is nicked or gapped by a reaction which is induced by proteases such as autodigested pronase, proteinase K, trypsin, chymotrypsin and subtilisin . The cleavage of the protease-sensitive sites is inhibited by protease inhibitors . The nicks or gaps induced by proteases can be demonstrated by nuclease S1 sensitivity of native DNA and by a change of the sedimentation rate of alkali-denatured DNA . The limit size of denatured DNA released after optimal protease treatment is 8.5 x 10(6) daltons (27 kilo bases) . The molecular weight of the native DNA pieces released after nuclease S1 degradation of DNA containing the protease-induced nicks or gaps is in the same order indicating that the protease-sensitive sites are alternatively arranged on the opposite DNA strands at an average distance of 13.5 kilo base pairs . Since the protease-induced nicks or gaps in phosphatase-treated DNA are not attacked by Escherichia coli polymerase I, one or both ends liberated by the protease treatment must be blocked by a material other than phosphate groups . The results are most compatible with peptide/protein linkers joining adjacent single-strand DNA subunits . Alternative explanations such as alkali-stable RNA linkers, protein-protected RNA linkers, site-specific nuclease contaminations in the protease preparations or cellular nucleases activated by the protease treatment are eliminated by the results presented in this paper.

J Biol Chem, 1980 Jul 25, 255(14), 7010 - 9
The identification by affinity chromatography of the rat liver ribosomal proteins that bind to elongator and initiator transfer ribonucleic acids; Ulbrich N et al.; Mixed yeast elongator-tRNAs (bulk tRNA lacking fRNAm,fMet), pure isoaccepting species of elongator-tRNAs (tRNAmMet and tRNAPhe), and purified initiator-tRNA (tRNAfMet) were each oxidized with periodate and the 3' terminus was coupled to Sepharose 4B through an adipic acid dihydrazide spacer . The rat liver ribosomal proteins that associated with the tRNAs were isolated by affinity chromatography and identified by electrophoresis in polyacrylamide gels . The rat liver ribosomal proteins that were bound to the elongator-tRNA preparations were L6, L35a, and S15; small amounts of a number of other proteins also associated with the nucleic acid . When initiator-tRNA (tRNAfMet) was immobilized on Sepharose, only L6 and L35a were bound; no 40 S subunit proteins associated with initiator-tRNA . No Escherichia coli proteins formed a complex with either eukaryotic initiator- or elongator-tRNAs.

J Biol Chem, 1980 Jul 25, 255(14), 6996 - 7001
Cloning and characterization of androgen-dependent mRNA from rat ventral prostate; Parker MG et al.; DNA complementary to three androgen-dependent mRNAs from rat ventral prostate has been cloned in the bacterial plasmid pAT 153 . DNA sequences coding for 20,000, 10,000, and 9,000 translation products, the precursors of polypeptides secreted in vivo (Parker, M . G., and Scrace, G.T . (1979) Proc . Natl . Acad . Sci . U.S.A . 76, 1580--1584) were identified in recombinant plasmids . The levels of mRNA coding for the 20,000 and 10,000 translation products were quantitated using cDNA probes and also by hybridization in situ with RNA that had been covalently bound to diazobenzyloxymethyl paper . Both mRNAs responded with similar kinetics to androgen withdrawal and testosterone stimulation . The sequences declined with nonlinear kinetics by at least 3 orders of magnitude after androgen withdrawal and are induced by testosterone without an appreciable lag, a 3-fold increase being detectable within 2 h . Analysis of the RNA bound to diazobenzyloxymethyl paper indicates that the mRNAs coding for the 20,000, 10,000, and 9,000 translation products contain 930, 640, and 550 nucleotides, respectively.

J Biol Chem, 1980 Jul 25, 255(14), 6941 - 6
Evidence for a repeated protein structure in the 30 S subunit of Escherichia coli ribosome; Subramanian AR; Protein S6 of Escherichia coli ribosome is an acidic protein on the 30 S subunit moiety and it exists in five forms differing only in the number of glutamic acid residues at the COOH terminus . I have determined the total number of copies of all five forms of S6 in the ribosome, using a wild type E . coli (MRE600) and a mutant strain (derivative of K12) that contains only one of these forms (Hitz, H., Schafer, D., and Wittmann-Liebold, B . (1977) Eur . J . Biochem . 75,497-512) . For this purpose, the ribosomes were labeled in vivo with 14C-, 3H-, or 35S-amino acids; bacteria were grown with a variety of carbon sources; and cells were harvested in midlogarithmic and stationary phases . The different forms of S6 were purified and a new procedure capable of electrophoretically separating the five forms of S6 from total ribosomal protein was developed . The results from these experiments show for the first time that there are two copies of protein S6 per ribosome . Thus, a repeat structure of a biochemically modified protein exists not only in the 50S subunit (protein L7/L12) as previously known, but also in the 30 S subunit of the ribosome.

J Biol Chem, 1980 Jul 25, 255(14), 6751 - 7
Biochemical and structural studies of the tetragonal crystalline modification of the Escherichia coli elongation factor Tu; Jurnak F et al.; The tetragonal crystalline form of the trypsin-treated Escherichia coli protein elongation factor Tu has been analyzed by biochemical and x-ray crystallographic techniques . The crystals contain two tightly associated polypeptide fragments of molecular weight 36,000 and 6,500 which represent 97% of the native enzyme . The crystals do not contain a short internal polypeptide fragment of 14 amino acids which dissociates from the native enzyme following mild trypsin digestion . The short fragment has been implicated in the aminoacyl-tRNA binding function and its location has been determined . The structure of the modified enzyme in the P4(3)2(1)2 crystal form has been determined to 5 A resolution by x-ray diffraction methods . The protein consists of two domains: the larger domain exhibits considerable alpha helical characteristics and the smaller domain has no identifiable secondary structural features . The relationship between the double domain structure of the enzyme and its biochemical properties is discussed.

J Biol Chem, 1980 Jul 25, 255(14), 6745 - 50
The NH2-terminal sequence of a precursor form of the arabinose binding protein; Wilson VG et al.; Cell-free arabinose binding protein (ABP) was synthesized using a mRNA-directed Escherichia coli S30 translation system . The source of the mRNA was a total cellular RNA extract from cultures of E . coli B/r ara A 39, induced for ABP production . Purification of in vitro ABP was effected by affinity chromatography on a column of purified anti-ABP coupled to Sepharose 4B, followed by Sephadex G-75 chromatography in 9% formic acid . The purified in vitro ABP was found to have a molecular weight approximately 3000 greater than native ABP . Comparison of the CNBr peptide fragments of native and in vitro ABP demonstrated an NH2-terminal extension of 23 amino acids not present in native ABP . The identities of 20 of the residues in the extension were established, and the characteristics of this region resemble the features proposed for signal sequences that function in protein secretion.

J Biol Chem, 1980 Jul 25, 255(14), 6559 - 51
The structure of D-galactose-binding protein at 4.1 A resolution looks like L-arabinose-binding protein; Quiocho FA et al.; The structure of D-galactose-binding protein, a receptor for both high affinity active transport system and chemotaxis in Escherichia coli, has been solved at 4.1 A resolution using three heavy atom derivatives . The molecule is ellipsoidal with dimensions of about 65 X 35 X 35 A . The overall shape of the molecule and the indication that the molecule consists of two domains separated by a cleft are reminiscent of the structure of L-arabinose-binding protein.

J Biol Chem, 1980 Jul 25, 255(14), 6826 - 31
The functional unit of polyenzymes . Determination by radiation inactivation; Kempner ES et al.; Recently, target analysis has been re-evaluated as a technique for the determination of molecular sizes (Kempner, E . S . & Schlegel, W . (1979) Anal . Biochem . 92, 2-10) . The technique yields the size of the functional unit, i.e . the minimal assembly of structures necessary for a given function such as an enzymatic activity . Using this method, we have not determined the sizes of the functional units for different enzymatic activities on the "arom" conjugate from Euglena, a polyenzyme catalyzing five sequential reactions in the shikimic acid pathway, and on two conjugates from Escherichia coli carrying both aspartokinase and homoserine dehydrogenase activities . In each conjugate, the size for different enzymatic activities was measured and found to be the same . When compared to the molecular weight obtained with other techniques, the target size matched either the entire conjugate (aspartokinase-homoserine dehydrogenase conjugates I and II) or half the unit ("arom" conjugate) . The information was obtained with minimal perturbation of the complexes and sparing laborious purification and reconstitution experiments . Tryptophan synthase was irradiated both as an intact conjugate and also as isolated subunits . In both structural forms, beta 2 was identified as the functional unit for the conversion of indole and serine to tryptophan . The results of this study give insight into the structural assembly of these polyenzymes.

Nucleic Acids Res, 1980 Jul 25, 8(14), 3215 - 27
Amplification of single-strand DNA binding protein in Escherichia coli; Chase JW et al.; An E . coli strain containing a recombinant plasmid carrying the E . coli ssbA+ gene has been shown to produce 12 to 15 fold increased amounts of single-strand DNA binding-protein relative to wild-type strains . In addition, a gamma transducing phage carrying the E . coli uvrA+ gene has been shown to also carry the ssbA+ gene and to be capable of producing increased amounts of binding protein.

J Biol Chem, 1980 Jul 25, 255(14), 6706 - 12
The iron center in ribonucleotide reductase from Escherichia coli; Petersson L et al.; Ribonucleotide reductase from Escherichia coli consists of two nonidentical subunits, proteins B1 and B2 . The active site is made up from both subunits . Protein B2 contains 2 iron atoms and a tyrosyl-free radical, which are essential for the enzymatic activity . The paramagnetic susceptibility of protein B2 has been measured over the temperature range 30-200 K . A deviation from the Curie law is observed at high temperatures, consistent with a structure of an antiferromagnetically coupled pair of high spin Fe(III) with an exchange coupling -J = 108(-20)+25 cm-1 . Electronic spectra are resolved into components from the iron center and the radical . A band at 600 nm is clearly identified and shown to have contributions from both components . The electronic absorptions of the tyrosyl radical of protein B2 are closely similar to those reported for phenoxy radicals of tyrosine and tritertiary butyl phenol . Determinations by EPR of the amount of free radical suggest the possibility of more than one radical per active protein B2 molecule . Reconstitution of the active site from apoprotein B2 and Fe(II) is only observed in the presence of oxygen . With Fe(III), no reconstitution is obtained . The additional physical data on the iron center of protein B2 strengthen the analogy with oxidized forms of hemerythrin . The most likely structure is an antiferromagnetically coupled pair of high spin Fe(III), possibly with a bridging oxo-group.

J Biol Chem, 1980 Jul 25, 255(14), 6794 - 8
A prepriming DNA replication enzyme of Escherichia coli . II . Actions of protein n': a sequence-specific, DNA-dependent ATPase; Shlomai J et al.; Protein n' of Escherichia coli is required for formation of the prepriming complex in replication of the single-stranded circle of phiX174 DNA . The protein, purified to near homogeneity, possesses ATPase (dATPase) activity in the presence of single-stranded, but not duplex, DNAs . Except for phiX174 DNA, ATPase activity is completely suppressed by coating the DNA with single strand binding protein (SSB) . phiX174 DNA possesses a unique sequence with a potential hairpin structure that is recognized as an effector (Shlomai, J., and Kornberg, A . (1980) Proc . Natl . Acad . Sci . U . S . A . 77, 799-803) . Sequences with secondary structure in SSB-coated M13 DNA which are recognized by RNA polymerase, and in coated G4 DNA by primase, are inert for protein n' . Approximately 30 of the 180 molecules of SSB bound to phiX DNA are destabilized by protein n' in an ATP-dependent reaction . These actions by protein n' may be important in recognizing an origin for forming the prepriming complex that leads to initiation of phiX complementary strand synthesis.

J Biol Chem, 1980 Jul 25, 255(14), 6789 - 93
A prepriming DNA replication enzyme of Escherichia coli . I . Purification of protein n': a sequence-specific, DNA-dependent ATPase; Shlomai J et al.; Protein n', an enzyme essential for in vitro conversion of single-stranded phiX174 DNA to the duplex replicative form, has been purified about 16,000-fold from Escherichia coli . The enzyme is a single polypeptide chain with a native molecular weight of 76,000; about 70 enzyme molecules are present in an E . coli cell . Nearly homogeneous preparations display an ATPase (dATPase) activity which depends on a unique sequence in the phiX174 DNA . Replicative activity of n' protein and its phiX174 DNA-dependent ATPase activity were present in a constant ratio during the latter stages of purification, upon sedimentation in a glycerol gradient, and during heat inactivation . Further studies of the properties of protein n' are presented in a succeeding paper.

Biochim Biophys Acta, 1980 Jul 24, 624(1), 130 - 41
Structural studies on aminoacyl-tRNA synthetases . A tentative correlation between the subunit size and the occurrence of repeated sequences; Potier S et al.; Recent studies have shown that those synthetases with subunits greater than 85,000 daltons contain extensive repeated sequences, whilst those with small subunits (40,000 daltons) do not . We have undertaken a comparative study of four aminoacyl-tRNA synthetases (glutamyl-, arginyl-, valyl-, and phenylalanyl-tRNA synthetases) with subunit sizes ranging from 56,000 to 130,000 daltons in an attempt to correlate the occurrence and extent of the repeats with the length of the polypeptide chain . Our results show that monomeric glutamyl-tRNA synthetase from Escherichia coli (56,000 daltons) contains few repeated sequences, whereas both subunits of yeast phenylalanyl-tRNA synthetase (alpha, 73,000 daltons; beta, 62,000 daltons) and yeast arginyl-tRNA synthetase (74,000 daltons) do have a significant amount of repeats . Thus 56,000 dalton appears to be the minimum size compatible with the existence of such repeats.

Nature, 1980 Jul 24, 286(5771), 356 - 9
A signal sequence is not sufficient to lead beta-galactosidase out of the cytoplasm; Moreno F et al.; Escherichia coli strains have been constructed in which lacZ, the gene for the cytoplasmic enzyme beta-galactosidase, is fused to lamB, the gene for an outer membrane protein . One such strain produces a beta-galactosidase which remains cytoplasmic even though it possesses the complete signal sequence of the lamB protein precursor at the amino-terminal end.

Nature, 1980 Jul 24, 286(5771), 346 - 51
Three-dimensional structure of Escherichia coli initiator tRNAfMet; Woo NH et al.; The crystal structure of Escherichia coli tRNAfMet an initiator transfer RNA, has been determined . While grossly similar to that of the chain-elongating yeast tRNAPhe, there are three major differences . One involves the folding of the anticodon loop; in particular, the position of the constant uridine, U33 . This difference was unexpected and may be of functional significance.

Biochemistry, 1980 Jul 22, 19(15), 3604 - 13
Raman spectra and conformational properties of ribosomes during various stages of disassembly; Thomas GJ Jr et al.; Raman spectra have been obtained on aqueous solutions of ribosomes, ribosomal subunits, ribosomal proteins, and ribosomal RNA extracted from both rat liver (RL) and Escherichia coli cells . The species examined from RL ribosomes are total ribosomes (80 S), large subunits (60 S), small subunits (40 S), EDTA-treated ribosomes, total rRNA, 28S RNA, 18S RNA, total protein, RNP particles from 80S ribosomes, and RNP particles from 60S subunits . The species examined from E . coli ribosomes are total ribosomes (70 S), large subunits (50 S), small subunits (30 S), mixtures of 50S and 30S subunits, total rRNA, 23S RNA, and 16S RNA . All rRNA molecules are shown by Raman spectroscopy to contain highly ordered secondary structures in which the backbone conformations are predominantly of the A-helix type . The present Raman spectra do not contain sufficient detail, however, to reach firm conclusions about the conformations of ribosomal proteins or their mutual interactions . RNA molecules within ribosomal particles remain highly ordered during various stages of ribosome disassembly, and their conformations are generally invariant to perturbations of ribosome structure, including dissociation into subunits, EDTA treatment, and partial deproteinization in a CsCl density gradient . However, when total protein extraction is carried out on ribosomes and subunits, small but significant changes in rRNA secondary structure are detected . The kind and magnitude of secondary structural change are different for different ribosomal particles . The Raman spectra of the ribosomes are compared also with spectra of a model ribonucleoprotein, the complex formed by poly(riboadenylic acid) and poly(L-arginine).

Biochemistry, 1980 Jul 22, 19(15), 3585 - 90
Quantitative measurements of membrane potential in Escherichia coli; Felle H et al.; By use of giant cells of Escherichia coli induced by growth in the presence of 6-amidinopenicillanic acid, membrane potentials have been measured by two completely independent techniques: directly with intracellular microelectrodes and indirectly from the steady-state distribution of {3H}tetraphenylphosphonium . Under a variety of conditions, the two methods yield values that agree very closely . Thus, with both techniques, the membrane potential approximates -85 mV (interior negative) at pH 5.0 and -142 mV at pH 8.0, with an average slope of -22 mV/pH unit over the range pH 5.0-7.0 . A parallel study of membrane vesicles prepared from giant cells was undertaken using tetraphenylphosphonium distribution alone as a measure of membrane potential . The vesicles were found to exhibit a much smaller slope of membrane potential vs . extracellular pH (about -6 mV/pH unit) than intact giant cells . The results indicate that distribution studies with these lipophilic cations provide an excellent measure of membrane potential and are discussed in relation to calculations of H+/substrate stoichiometry for protonsymport systems in E . coli.

Biochemistry, 1980 Jul 22, 19(15), 3491 - 5
Defective assembly of ribonucleic acid polymerase subunits in a temperature-sensitive alpha-subunit mutant of Escherichia coli; Kawakami K et al.; The subunit assembly of RNA polymerase was investigated for the temperature-sensitive Escherichia coli strains carrying the mutation rpoA101 or rpoA112 in the gene encoding its alpha subunit, In cells carrying rpoA112, the sequential assembly of enzyme subunits is blocked at an early step, i.e., either the dimerization of altered alpha subunit or the subsequent association of altered alpha dimer with beta subunit . As a result, the unassembled free alpha subunit accumulates and the unassembled beta and beta' subunits are degraded rapidly, in particular at a nonpermissive temperature . The assembly defect is accompanied by an overproduction of enzyme subunits apparently due to the decrease in the concentration of repressor holoenzyme involved in the autogenous regulation . These results together with the previous observations {Ishihama, A., Shimamoto, N., Aiba, H., Kawakami, K., Nashimoto, H., Tsugawa, A., & Uchida, H . (1980) J . Mol . Biol . 137, 137-150} indicate that the temperature-sensitive growth of rpoA112 mutants is attributed to the assembly defect of RNA polymerase as well as to the thermolability of assembled polymerase . In contrast, the altered alpha subunit in a mutant carrying rpoA101 is assembled into the polymerase structure as efficiently as in wild-type cells; nevertheless, both beta and beta' subunits are rapidly degraded in this mutant . This indicates that the mutant polymerase is structurally different from the metabolically stable wild-type enzyme . Thus, the ts character of rpoA101 mutant is explained by the alteration in the structure and function of assembled RNA polymerase.

Z Gesamte Inn Med, 1980 Jul 15, 35(14), 27 - 30
{Chronic pyelonephritis from a clinical viewpoint}; Precht K et al.; The chronic pyelonephritis is an unspecific, bacterial, focal, interstitial nephritis with faculative participation of the pyelon . It is differentiated between an obstructive (secondary) and non-obstructive (primary) form . It is referred to the importance of risk factors and risk groups deriving themselves from this . Without doubt, the chronic pyelonephritis is the most frequent renal disease which is confirmed by new statistics of morbidity . The diagnostics still renders difficulties . In a course poor in symptoms it is not thought of the existence of the disease . For the rational dignostics in practice a step plan is recommended . In every case diagnostics should precede therapy . A therapeutic nihilism is to be avoided . A schematic treatment used without criticism and without taking into consideration individual peculiarities, secondary diseases, pregnancy and so on is to be abandoned . Short-term therapy and long-term prevention must be tuned one to another and possibly rationally combined . A plan for the long-term control in the renal dispensary is proposed.

Biochem J, 1980 Jul 15, 190(1), 157 - 70
Intermediates in the assembly of ribosomes by a mutant of Escherichia coli; Butler PD et al.; Escherichia coli strain 15--28 is a mutant that accumulates ribonucleoprotein ('47 S') particles during exponential growth . These particles contain mature 23 S rRNA, but lack three of the proteins of the larger ribosomal subunit, to which they are a precursor . In organisms growing at 20 degrees C, assembly of 47 S particles involves three intermediates that contain precursor 23 S rRNA, one of which has the same sedimentation properties as 47 S particles . Assembly of 50 S ribosomal subunits in the parent strain is 'normal' . There are three intermediates; each contains precursor 23 S rRNA, and one cannot be distinguished from completed subunits by sedimentation . Synthesis of 30 S ribosomal subunits in parent and mutant strains is qualitatively similar, but quantitatively different . When growth is at 37 degrees C, assembly in the mutant alters . There are now two sequential precursors to 47 S particles . Both contain precursor 23 S rRNA; one has the same sedimentation coefficient as 47 S particles . In some respects, synthesis in the mutant proceeds as though 47 S particles, rather than 50 S ribosomal subunits, are the end-product of assembly.

Nucleic Acids Res, 1980 Jul 11, 8(13), 2921 - 37
Transfer RNA genes of Drosophila melanogaster; Dudler R et al.; Three recombinant plasmids containing randomly sheared genomic D . melanogaster tRNAs have been identified and characterized in detail . One of these, the plasmid 14C4, has a D . melanogaster (Dm) DNA segment of 18 kb, and has three tRNA2Arg and two tRNAAsN genes . The second plasmid, 38B10, has tRNAHis genes, while the third plasmid, 63H5, contains coding sequences for tRNA2Asp . The Dm DNA segments in each recombinant plasmid are derived from unique cytogenetic loci . 14C4 is from 84 F, 38B10 is from 48 F and 63H5 is from 70 A.

Nucleic Acids Res, 1980 Jul 11, 8(13), 3011 - 27
Nucleotide sequence of the gene ompA coding the outer membrane protein II of Escherichia coli K-12; Beck E et al.; A nucleotide sequence of 2271 basepairs has been determined from cloned E . coli DNA which contains ompA . Withing that sequence, starting at nucleotide 1037, an open translational reading frame encodes a protein of 367 amino acids which starting with amino acid 22 agrees with the primary structure of protein II . The preceeding 21 amino acids constitute a typical signal sequence . There is a non-translated region of 360 nucleotides in front of the translational start . The insertion point of an IS1 element 110 nucleotides upstream from the start codon and an amber codon at the position of amino acid residue 28 have been localized in the DNA from two ompA mutants.

Nucleic Acids Res, 1980 Jul 11, 8(13), 2907 - 20
Some characteristics of processing sites in ribosomal precursor RNA of yeast; Veldman GM et al.; The DNA sequences of the intergenic region between the 17S and 5.8S rRNA genes of the ribosomal RNA operon in yeast has been determined . In this region the 37S ribosomal precursor RNA is specifically cleaved at a number of sites in the course of the maturation process . The exact position of these processing sites has been established by sequence analysis of the terminal fragments of the respective RNA species . There appears to be no significant complementarity between the sequences surrounding the two termini of the 18S secondary precursor RNA nor between those surrounding the two termini of 17S mature rRNA . This finding implies that the processing of yeast 37S ribosomal precursor RNA is not directed by a double-strand specific ribonuclease previously shown to be involved in the processing of E . coli ribosomal precursor RNA {see Refs 1,2} . The processing sites of yeast ribosomal precursor RNA described in the present paper are all flanked at one side by a very {A+T}-rich sequence . In addition, sequence repeats are found around the processing sites in this precursor RNA . Finally, sequence homologies are present at the 3'-termini {6 nucleotides} and the 5'-termini {13 nucleotides} of a number of mature rRNA products and intermediate ribosomal RNA precursors . These structural features are discussed in terms of possible recognition sites for the processing enzymes.

Nucleic Acids Res, 1980 Jul 11, 8(13), 3055 - 64
Sequence rearrangement and duplication of double stranded fibronectin cDNA probably occurring during cDNA synthesis by AMV reverse transcriptase and Escherichia coli DNA polymerase I; Fagan JB et al.; Two cloned cDNAs derived from the mRNA for cell fibronectin have been sequenced, providing evidence that transcription with AMV reverse transcriptase or Escherichia coli DNA polymerase I may not always result in double stranded cDNA that is exactly homologous with its mRNA template . Instead, the sequences of these cloned cDNAs are consistent with the duplication and rearrangement of sequences during synthesis of double stranded cDNA.

Nature, 1980 Jul 10, 286(5769), 176 - 8
Efficiency of the adaptive response of Escherichia coli to alkylating agents; Cairns J; When cultures of Escherichia coli are exposed to a low level of the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) they accumulate mutations for about 20 min and then become resistant to further mutagenesis by that level of MNNG . This 'adaptive response, has been shown to be due, at least in part, to induction of the rapid repair of O6-alkylguanine which appears to be the main mutagenic and carcinogenic lesion produced by simple alkylating agents . A similar kind of repair has been demonstrated in the livers of rats exposed to nitrosamines, and this presumably helps to protect animals against carcinogenesis by the various alkylating agents thjat are widespread in our environment . It seemed important, therefore, to find out just how effectively such adaptive responses can control mutations rates.

J Biol Chem, 1980 Jul 10, 255(13), 6228 - 33
Some effects of indole on the interaction of amino acids with tryptophanase; Kazarinoff MN et al.; Although indole is a potent inhibitor (KI = 0.01 mM) of pyruvate formation from substrates of tryptophanase (EC 4.1.99.1, from Escherichia coli), we could not detect binding of indole to free tryptophanase (KD greater than 1.0 mM) . However, indole, skatole, and toluene increased the affinity of tryptophanase for certain inhibitory amino acids . Binding of amino acids with small side chains (e.g . Ala, Gly) was increased, but there was little or no effect on the binding of amino acids with bulky side chains (e.g . norvaline, ethionine) . These effects were quantitated by using changes in the absorption spectra of the enzyme . amino acid complexes . Indole decreases the absorbance obtainable at 500 nm for amino acids with small hydrophobic side chains (L-Ala, Gly), increases this absorbance for amino acids with small polar side chains (beta-cyano-L-alanine), and does not change the spectra of tryptophanase complexes with amino acids with bulky side chains, i.e . amino acids whose binding affinities are unaffected by indole . These spectral differences are interpreted in terms of an effect of bound indole (or side chain binding) on the partitioning of the bound amino acid between catalytic forms of the enzyme . The data indicate that substrate-induced conformational changes occur at the enzyme active site that generate a high affinity indole-binding site during catalytic turnover of tryptophanase and are important in the catalytic functioning of the enzyme . These changes also explain reproducible differences in KI values observed previously for amino acids in different assay systems used for steady state kinetic inhibition studies . The optimal conditions for the growth of E . coli for tryptophanase production are outlined, together with a procedure for purification of holotryptophanase.

J Biol Chem, 1980 Jul 10, 255(13), 6018 - 9
Euglena gracilis chloroplast EF-Ts . Evidence that it is a nuclear-coded gene product; Fox L et al.; Extracts of Euglena gracilis cells contain high levels of elongation factor (EF)-Ts (EF-Tschl) activity which can be assayed by measuring the rate of exchange of GDP with Escherichia coli EF-Tu . GDP . The appearance of EF-Ts activity in E . gracilis cells is light-stimulated, suggesting that the EF-Ts is required for chloroplast function . However, based on experiments with a mutant of E . gracilis lacking chloroplast DNA, as well as studies on the effect of antibiotics on EF-Ts synthesis, it is concluded that the EF-Tschl gene is nuclear-coded.

J Biol Chem, 1980 Jul 10, 255(13), 6205 - 11
Bovine thymus poly(adenosine diphosphate ribose) polymerase . Physical properties and binding to DNA; Ohgushi H et al.; Purified bovine thymus poly(adenosine diphosphate ribose) polymerase is a monomeric protein with a single polypeptide chain having a molecular weight of approximately 130,000, determined by sodium dodecyl sulfate-gel electrophoresis, analytical ultracentrifugation, and gel filtration . A high frictional ratio (1.81) indicated that the molecule has an elongated shape, or a high solvation, or both . The enzyme is a basic protein (pI 9.8), and amino acid analysis showed a relatively high lysine content . The enzyme activity is dependent on double-stranded DNA and is solely correlated with single- or double-stranded breaks on the DNA . Filter binding assay technique showed that the enzyme-activating efficiency of DNA correlated sufficiently with its enzyme-binding efficiency . Thus, a very high enzyme-activating efficiency of a DNA fraction (active DNA) which was separated from the crude enzyme fraction is mainly due to its high enzyme-binding efficiency . It was also shown that single-stranded DNA and heparin had a strong inhibitory effect on the binding of the enzyme to double-stranded DNA, whereas competitive inhibitors did not affect the binding, We interpret these results to indicate that the binding of the enzyme to double-stranded DNA is a prerequisite step to its catalytic activity and has a dual function: (a) to position the enzyme on specific binding sites such as single- or double-stranded breaks on the DNA, and (b) to induce an active conformation of the enzyme.

J Biol Chem, 1980 Jul 10, 255(13), 6307 - 13
The effect of alcohols on guanosine 5'-diphosphate-3'-diphosphate metabolism in stringent and relaxed Escherichia coli; Mitchell JJ et al.; The effects of a series of alcohols on the stringent response system of Escherichia coli were studied . The alcohols used could be divided into two groups on the basis of the response of pppGpp and ppGpp to the growth downshift induced by the alcohols . The cells responded to the alcohols, methanol, ethanol, and propanol, as if they were being starved of amino acids . In the stringent strain CP78 these alcohols induced pppGpp and ppGpp accumulation and curtailed RNA synthesis, whereas in the relaxed strain CP79, both of these responses were absent . It was determined that this response was most likely due to an interference by these alcohols with the uptake of amino acids required by these strains . By contrast both stringent and relaxed cells elevated their level of ppGpp and decreased RNA accumulation when treated with butanol or pentanol . This response is similar to the effect of carbon source limitation . It was determined that the elevation of ppGpp in the stringent strain was primarily the result of increased ppGpp synthesis in response to these alcohols . In the relaxed strain the rise in ppGpp was dependent on a decrease in ppGpp degradation coupled with a moderate increase in ppGpp synthesis . This stimulation of ppGpp synthesis in relaxed cells, although small, suggests the existence of an enzyme distinct from stringent factor which is capable of synthesizing ppGpp . Data are presented which suggest that the activity of this enzyme is coupled to the potential for protein synthesis and energy availability of the cell, perhaps being regulated by the overall ratio of unchanged to amino-acylated tRNA.

Biochemistry, 1980 Jul 8, 19(14), 3400 - 6
Coenzyme binding site of glutamate decarboxylase; O'Leary MH et al.; Dissociation constants have been measured for the binding of a variety of simple analogues of pyridoxal 5'-phosphate to apoglutamate decarboxylase . Compounds studied have a simple alkyl or aryl group and a negatively charged substituent (phosphate, phosphonate, phosphoramidate, sulfate, sulfonate, or carboxylate) . Optimum binding to the phosphate binding site of the enzyme is achieved by compounds having a double negative charge and a tetrahedral geometry . Planar anions and monoanions bind considerably less well . These and previous data are used to to derive the magnitudes of the contributions of various coenzyme functional groups to the strength of the apoenzyme-coenzyme interaction.

Biochemistry, 1980 Jul 8, 19(14), 3245 - 53
Cycling of ribonucleic acid polymerase to produce oligonucleotides during initiation in vitro at the lac UV5 promoter; Carpousis AJ et al.; High-resolution gel electrophoresis has been used to detect and quantitate promoter-specific oligonucleotides produced during initiation of transcription in vitro at the lactose operon (lac) UV5 promoter . The resolved products are RNA species of various lengths which correspond to the initial lac mRNA sequence . Quantitation shows that many oligonucleotides can be formed per preinitiation complex, including species as long as hexanucleotide . Synthesis occurs without dissociation of the enzyme, as evidenced by levels of synthesis in the presence of heparin, a selective inhibitor of free RNA polymerase . Thus, RNA polymerase cycles at this promoter in vitro producing oligonucleotides reiteratively . In general, the yield of oligonucleotides decreases when the total concentration of all four substrates is increased or when a missing nucleoside triphosphate substrate is added . Nevertheless, oligonucleotide synthesis persists under all conditions tested . Strikingly, the dinucleotide always represents 50% of the total of all oligonucleotides, even when conditions are manipulated to cause a 100-fold variation in this total . This shows that, after formation of the first phosphodiester bond at the lac UV5 promoter, dissociation of the dinucleotide is as likely as formation of the second phosphodiester bond . As discussed above, after release of a small RNA, RNA polymerase may then begin another RNA chain, which is again subject to premature release . These considerations lead to a model in which RNA polymerase cycles to produce oligonucleotides during initiation of transcription at the lac UV5 promoter in vitro . Production of a long RNA transcript is then essentially an escape from this cycling reaction . The drug rifampicin, which drastically inhibits escape to produce RNA, limits, but dose not prevent, the cycling reaction.

Biochim Biophys Acta, 1980 Jul 8, 591(2), 471 - 82
Low-temperature spectral and kinetic properties of cytochromes in Escherichia coli K-12 grown at lowered oxygen tension; Poole RK et al.; Escherichia coli K-12 was grown in batch culture in a medium containing succinate as carbon source, supplemented with casein hydrolysate, and with a rate of oxygen supply that resulted in dissolved O2 tension falling to 10% of saturation in the latter stages of growth . Cytochromes in such cells were qualitatively indistinguishable from those present in cells grown under conditions of vigorous aeration where dissolved O2 tensin remained greater than 80% saturation . Spectra recorded at 77 K and their fourth-order finite difference analyses revealed the absence of cytochrome b-558 and only low concentrations of cytochromes a1 and d(a2) . At low temperatures, the reaction of cytochrome o with O2 in intact cells, grown under lowered O2 tension, proceeds through the same stage as observed previously in cells grown with vigorous aeration (Poole, R.K., Waring, A.J . and Chance, B . (1979) Biochem . J . 184, 379-389) . However, much higher temperatures are required for comparable progress of the reaction in cells grown at lowered O2 tensions . AT 91 degrees C, the reaction with O2 involves ligand binding to give intermediate(s) with spectral characteristics similar to those of the reduced oxidase-CO complex . Temperatures of approx . -79 degrees C are required for the observation of biphasic kinetics and the attainment of an 'end point' in the reaction, features that are seen at temperatures below -98 degrees C in cells from vigorously-aerated cultures . At -32.5 degrees C, oxidation of cytochrome o is observed . The energy of activation for this reaction at low temperatures is 29.9 kJ x mol-1 . Binding with CO, in contrast to binding with O2, is characterized by high photolytic reversibility and appears to be less affected by the degree of aeration of cells during growth.

Am J Vet Res, 1980 Jul, 41(7), 1002 - 7
Immunologic responses in colostrum-fed and colostrum-deprived calves; Clover CK et al.; The influence of colostrum on several aspects of the neonatal immune response, including lymphocyte reactivity in vitro, was examined in the calf from birth through 96 hours after delivery . Using a whole blood microculture assay, the blastogenic response of peripheral blood lymphocytes (PBL) incubated with phytohemagglutinin (PHA), pokeweed mitogen (PWM), or Escherichia coli lipopolysaccharide (LPS) were examined for colostrum-fed (CF) and colostrum-deprived (CD) calves . The PHA and PWM stimulated significant levels of {3H}thymidine incorporation in both calf groups, although LPS was only marginally mitogenic . However, PBL from CD calves during the first 24 hours after delivery had significantly greater amounts of total label incorporation in response to the three mitogens as compared with the label in PBL from CF calves . Differential and total WBC counts differed markedly between CF and CD calves during the first 48 hours after delivery; CF animals had significantly increased leukocyte counts at 6, 12, and 24 hours, due primarily to transient neutrophilia . Blood sera collected from calves before ingesting colostrum contained trace amounts of immunoglobulin (Ig) M and IgG; all three classes of Ig (M, G, and A) were present in significant amounts in sera of calves after colostrum feeding . The observed effects of colostrum on various components of the immune system are discussed.

Br J Cancer, 1980 Jul, 42(1), 121 - 8
Effect of methionine deprivation on methylation and synthesis of macromolecules; Tisdale MJ; The growth of 4 tumour-cell lines (Walker rat mammary carcinoma (W-256), a mouse lymphoma (TLX5), a mouse bladder carcinoma (MB) and a human bladder carcinoma (EJ) was much reduced when methionine in the culture medium was substituted by homocysteine . In contrast, a human embryonic fibroblast line grew equally well under such conditions . Although homocysteine alone was unable to support growth of W-256 it stimulated growth at low methionine concentrations . When W-256 was cultured for 24 h in medium containing homocysteine only, the extent of methylation of nucleic acids and the acid-soluble pool of methionine were decreased . However, under such conditions there was an increased methylase activity towards both endogenous substrate and E . coli tRNA . The effect of methionine removal was to cause a large increase in the Vmax value for methylation of tRNA, without any change in the Km value towards S-adenosyl-L-methionine (SAM) . For both W-256 and TLX5, methionine deprivation caused a rapid inhibition of RNA biosynthesis, followed by inhibition of DNA synthesis, while protein synthesis tended to increase . This suggests that the inability of W-256 and TLX5 to survive and grow in methionine-deficient, homocysteine-supplemented medium is not due to insufficient methionine for protein biosynthesis, but may be related to an enhanced methylating activity of some tumour-cell lines.

Mol Biol (Mosk), 1980 Jul-Aug, 14(4), 951 - 5
{Study of the secondary structure of L-asparaginase over a broad range of pH values}; Illarionova NG et al.; Conformation of L-asparaginase from E . coli had been studied by spectropolarimetry methods (CD and ORD) in pH region from 2.5 to 12.5 . Results were correlated with the change in enzyme activity . It was shown that the secondary structure of the enzyme degraded when pH was smaller than 5 and larger than 10 . Degradation was accompanied by the dissociation of the agregative form on individual subunits . In pH region form 5 to 10 the secondary structure of L-asparaginase does not change . Secondary structure parameters of L-asparaginase calculated from the known aminoacid consequence by means of two independent theoretical methods are in satisfactory agreement with results of CD and ORD analysis spectra . It is proposed that there exists a hydrofobic slit into which the decapeptid containing serine from the L-asparaginase active site is plunged.

Ann Microbiol (Paris), 1980 Jul-Aug, 131B(1), 31 - 7
A new in vitro technique for attachment to intestinal villi using enteropathogenic Escherichia coli; Girardeau JP; The author describes a new in vitro technique for detecting attachment of enteropathogenic Escherichia coli to isolated intestinal villi.

Ann Microbiol (Paris), 1980 Jul-Aug, 131B(1), 1 - 10
Inhibition of Escherichia coli haemagglutination by phenothiazines; Roland F; The enterotoxigenic Escherichia coli strain H-10407 (078-H11) of Evans, possessing a colonization factor antigen (CFA/I) and haemagglutinating in the presence of mannose, was tested as to its ability to cause haemagglutination in the presence of phenothiazines . The phenothiazines (chlorpromazine, thioridazine, prochlorperazine, triethylpiperazine, promethiazine and promazine) were able to inhibit E . coli haemagglutination when added to the complex E . coli-erythrocytes . The most potent inhibitors were prochlorperazine and thioridazine, which inhibited E . coli haemagglutination in 1 min at a concentration of 1.5 mg/ml . The less potent was promethazine that inhibited haemagglutination at 6 mg/ml . Once haemagglutination had occurred the phenothiazines were able to reverse it, to "unhood" the E . coli from the erythrocytes . Prochlorperazine at a concentration of 0.4 mg/ml could reverse haemagglutination after 1 h contact with the E . coli erythrocytes complex . E . coli H-10407 grown in the presence of phenothiazines lost its haemagglutinating activity . The resulting non haemagglutinating E . coli recovered its haemagglutinating activity when recultured in a prochlorperazine free medium.

Res Vet Sci, 1980 Jul, 29(1), 133 - 4
Effect of Escherichia coli O78 endotoxin on plasma lipids in the domestic fowl; Curtis MJ et al.; The injection of fasting nine- to 10-week-old chickens with endotoxin from a pathogenic avian strain of Escherichia coli (1 mg/kg iv) reduced the triglyceride, cholesterol and phospholipid content of the plasma 2 to 5 h afterwards . This effect was similar to that of an E coli infection and opposite to that produced in mammals . There was a transient rise in the cholesterol level within the first hour.

Arch Int Pharmacodyn Ther, 1980 Jul, 246(1), 19 - 27
Endotoxin-induced inhibition of gastric emptying rate in the rat . The effect of repeated administration and the influence of some antipyretic agents; van Miert AS et al.; Intravenous injection of endotoxin from E . coli O (111)B(4) caused inhibition of gastric emptying rate in conscious Wistar rats . Tolerance induced by repetitive daily intraperitoneal administration of the endotoxin, resulted in a complete abolition of this effect . Insulin, administered subcutaneously, stimulated gastric emptying rate . Pretreatment with this drug opposed the endotoxin-induced inhibitory effect completely . Pretreatment with indomethacin only had a partial antagonistic influence, while other drugs such as flurbiprofen, suprofen and novaminsulphonum had no significant effect upon endotoxin-induced inhibition of gastric emptying rate . Previous studies suggested that some effect of endotoxin other than stimulation of the biosynthesis of prostaglandins should be considered . The results of the present study suggest a similar conclusion . The nonsteroidal anti-inflammatory agents used, did not modify the normal course of gastric emptying in the control rats.

Acta Physiol Pol, 1980 Jul-Aug, 31(4), 391 - 4
Effect of fever on blood copper level in adrenalectomized animals; Kielczewska-Mrozikiewicz D et al.; In the experiments on adrenalectomized animals it was shown that the fever-associated rise in the blood copper level was absent in these animals . Hydrocortisone administration to adrenalectomized animals restored the normal reactivity of the animals to injections of pyrogens.

Scott Med J, 1980 Jul, 25(3), 227 - 9
Infection after depressed fracture in the west of Scotland; Sande GM et al.; Of 216 compound depressed fractures of the skull seen between the years 1974-1978, nine (4%) became infected . This is significantly less than the 10% found in previous years . Efforts are being intensified to train primary surgeons, stressing the importance of immediate referral and early treatment.

Ann Immunol (Paris), 1980 Jul-Aug, 131D(1), 103 - 9
Differentiation signal defect of splenic cells from LPS-treated mice; Portnoi D et al.; Spleen cells from mice sensitized with 10 microgram of LPS given intravenously are unable, when stimulated in vitro 48 h after this treatment, to respond to sheep erythrocytes (SRBC) . Addition of T-cell replacing factors (TRF) to these cells restores their capacity to mount an anti-SRBC immune response . Killing of the cells proliferating under antigen stimulation by highly radioactive thymidine leads to the suppression of the anti-SRBC response observed in the presence of TRF . These experiments suggests that the proliferative events leading to the expansion of B cell precursors under antigen stimulation is not impaired by the treatment by LPS . These preliminary data show that the defect is linked to the lack of signals leading to the differentiation of B cells into antibody-secreting cells.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 4170 - 4
A specific transcription factor that can bind either the 5S RNA gene or 5S RNA; Pelham HR et al.; 5S ribosomal RNA specifically inhibits transcription of cloned repeating units of 5S DNA in a nuclear extract of Xenopus oocytes . The inhibition can be explained by the interaction of 5S RNA with a transcription factor that binds specifically to a control region located within the 5S RNA gene . This transcription factor is identical to an abundant cytoplasmic protein that is known to be complexed with 5S RNA in immature Xenopus oocytes . Thus the presence of large amounts of this protein in these cells can account for both the high rate of synthesis and the subsequent storage of 5S RNA to ribosome synthesis.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 4147 - 51
Transcription of tRNA genes in vivo: single-stranded compared to double-stranded templates; Cortese R et al.; The expression of cloned tRNA genes has been studied by injecting single-stranded and double-stranded DNA templates into Xenopus oocyte nuclei . In both forms the genes are faithfully transcribed after injection . Some single-stranded DNA is converted into double-stranded DNA in the oocyte nucleus . This conversion is necessary for the expression of the injected tRNA gene: no tRNA transcription is observed when DNA synthesis is inhibited . We conclude that single-stranded DNA does not serve as a template for faithful transcription of this gene in injected oocytes.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 4007 - 10
Ribosomal protein L7/L12 is required for optimal translation; Pettersson I et al.; We have tested the performance in vitro of Escherichia coli ribosomes containing or lacking the protein L7/L12 . When the experiments are performed in an optimized mixture of ions (polymix), L7/L12 is required for maximal rate of synthesis as well as for minimal missense error frequency . The results in conventional Tris/Mg2+/NH4Cl buffers are different; in these buffers, only the rate of synthesis is strongly dependent on the presence of L7/L12 . In addition, we show that there is a large difference between the optimal Mg2+ concentration required for speed of translation and that for accuracy of translation in conventional buffer . These optima are very close in polymix . Finally, we show that the contribution of L7/L12 to the speed of translation is obscured in translation systems that are limited by substrates . We conclude that it is not possible to analyze details of the mechanism of translation in conventional buffers.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3993 - 7
Copy-number mutants of the plasmid carrying the replication origin of the Escherichia coli chromosome: evidence for a control region of replication; Ogura T et al.; A composite plasmid (pXX11) was constructed by joining of an oriC plasmid (pMCR115) carrying the replication origin (oriC) of the Escherichia coli chromosome and a mini-F plasmid (pSC138) carrying the ampicillin-resistance gene (bla) . Plasmid pXX11 can replicate, by using oriC, in Hfr cells and mafA mutant cells that cannot support replication of an F plasmid . This plasmid is stably maintained in these host cells during cell growth even under nonselective conditions by use of the partition mechanism of the mini-F genome . In contrast to other oriC plasmids reported previously, pXX11 has no detectable effect on host cell growth . Higher copy-number (Cop-) mutants of pXX11 were isolated, and some of them were found to carry an insertion or deletion within a region derived from the E . coli chromosome . This region, designated cop (copy number), covers about 0.7 kilobase pair and is located approximately 3 kilobase pairs away from the oriC region at the side opposite the asn gene . Evidence suggests that the normal cop region locted on the oriC plasmid acts to reduce the copy number of the plasmid . Plasmid pXX11 complements the uncB402 mutation located on the host chromosome, but some of the Cop- plasmids do not, suggesting that the cop region is vey closely linked to uncB.

J Pathol, 1980 Jul, 131(3), 221 - 33
Effects of endotoxin on the histology of intact and athymic mice infected with Plasmodium vinckei petteri; Clark IA et al.; Apparently healthy intact and athymic mice with low to moderate parasitaemias of P . vinckei petteri are very susceptible to the harmful effects of Endotoxin (LPS) . The histological changes seen in such mice after injection of a small dose of LPS closely resemble those seen in mice terminally infected with this parasite . Thus the onset of pathology could be hastened by giving a little LPS . Both groups of intact mice showed foci of hepatic necrosis, severe necrosis in the thymus, and light to moderate necrosis in the germinal centres of the splenic white pulp and Peyer's patches . In contrast liver necrosis was seen in very few of the terminally ill athymic mice and in none of the athymic mice given LPS . Our results imply that the lesions produced by LPS in the liver and lymphoid organs of apparently healthy mice with low to moderate parasitaemias would have eventually developed, without the help of extrinsic LPS, as the parasitaemia rose further and the infection ran its normal fatal course . This would be consistent with an intrinsic LPS-like activity in these terminally infected mice . One possible contributor to the liver necrosis seen in this infection is a T-dependent mediator reported to block enzyme induction . Any proposal for the mechanism of this damage must explain its rarity in athymic mice, its induction by LPS in intact but not athymic mice, and host differences in parasite density at which it occurs.

Immunology, 1980 Jul, 40(3), 473 - 82
Effect of lipid A-associated protein and lipid A on the expression of lipopolysaccharide activity . I . Immunological activity; Izui S et al.; A detailed investigation has been made of the contribution of the various chemical moieties of bacterial endotoxins, namely lipid A-associated protein (LAP), lipid A and O-antigen polysaccharide to a number of the immunological activities of these active bacterial products . Advantage was taken of the availability of antigenically identical endotoxin preparations from Escherichia coli 0111:B4 which differed greatly in their content of LAP and/or lipid A . The capacity to initiate in vitro proliferative responses in murine splenocytes was in a large part related to the presence of LAP with a less potent, although still critical, dependence upon lipid A . On the other hand, the in vivo polyclonal antibody response was dependent only upon lipid A . In this respect, the presence of LAP had no apparent effect on the stimulation of nonspecific low affinity antibody . All preparations, regardless of LAP and lipid A content, stimulated similar in vivo enhancement of antibody responses to a protein antigen (adjuvanticity) and specific immune responses to the endotoxin polysaccharide antigen . The results emphasize the lack of correlation between in vitro B lymphocyte proliferative responses and in vivo immunostimulatory responses of bacterial endotoxin preparations . These data also suggest a minimal contribution of LAP to in vivo responses and an extremely limited contribution of lipid A to the adjuvant activity and the primary immune response to O-antigen polysaccharide.

Int J Radiat Biol Relat Stud Phys Chem Med, 1980 Jul, 38(1), 63 - 82
Radiochemical cross-linking of proteins to RNA within ribosomal subunits from E . colil MRE 600; Giocanti N et al.; Irradiation in vitro of 30S and 50S ribosomal subunits from E . coli MRE 600 by gamma rays from cobalt 60, in the absence of oxygen, results in the formation of covalent links between the RNAs and some ribosomal proteins . At low radiation doses, just sufficient to keep the integrity of the ribosome structure, the phenomenon appears highly specific . In the 30S irradiated particle, protein S1 attaches to 16S RNA; in the 50S irradiated particle, the proteins L3, L13, L19, L21, L22 and L24 are linked to 23S RNA . The mechanism of formation of these cross-links and their contribution to the study of the tridimensional ribosome structure are also discussed.

Biofizika, 1980 Jul-Aug, 25(4), 654 - 7
{Biphasic energy-dependent potassium ion absorption by Escherichia coli cells}; Durgar'ian SS et al.; The E . coli cells remove acid and accumulate potassium ions in two phases in the presence of glucose . The first phase (5-7 min) takes place only with an increase of external osmolarity; the second phase begins after 20 min and is not sensitive to alteration of the osmotic pressure . Potassium efflux occurs between two phases of K+-accumulation in alkaline media . Replacement of glucose by lactate results in a decrease of the first phase and abolition of the second one . The initial rate of K+-uptake for the first phase is a saturation curve in the range of 6 mM of external potassium concentration . These data indicate that the osmosensitive system of K+-uptake is connected with the first phase.

Antimicrob Agents Chemother, 1980 Jul, 18(1), 200 - 5
New translocation sequence mediating tetracycline resistance found in Escherichia coli pathogenic for piglets; Jorgensen ST et al.; A discrete piece of deoxyribonucleic acid coding for tetracycline (Tc) resistance was found to move from one R plasmid to another in an Escherichia coli strain which is pathogenic for piglets . Since this phenomenon took place also in rec strains, the Tc segment was classified as a transposon and called Tn804 . Restriction enzyme analysis with EcoRI, BglII, and HindIII indicated that Tn804 is related to Tn10, a well-known transposon that codes for resistance to tetracycline . Hybridization between plasmids carrying the two transposons provided proof of homology between Tn10 and prt of Tn804 . Electron microscopic studies showed a transposon-like structure composed of one loop-stem structure with inverted repetitions of approximately 0.9 megadaltons inserted into the loop of a second loop-stem structure . It is suggested that Tn804 is composed of Tn10 plus another transposable sequence.

J Gen Microbiol, 1980 Jul, 119(1), 155 - 64
Ultrastructural changes in Escherichia coli grown in divalent cation-deficient medium; Arancia G et al.; Escherichia coli strains B and K12 could grow in very limiting conditions of divalent cation deficiency . Growth curves showed a long lag period of about 30 h, followed by an exponential phase bringing the bacterial concentration to about 10(7) ml-1, with a 24 min doubling time, while the growth curves of control cultures were characterized by short lag periods, maximum populations of about 10(9) ml-1 and an 18 min doubling time . The DNA/protein ratio in bacteria grown in deficient medium was 0.48 compared with 0.21 for control bacteria . Significant differences were found in the ultrastructure of the two types of bacteria . Freeze-etched control cells showed the typical appearance with the protoplasmic fracture face of the cytoplasmic membrane (PFC) having a random distribution of intramembranous particles . Bacteria growing in deficient medium in exponential phase presented several particle-free areas on the PFC . At the beginning of the stationary phase, the particle-free zones became larger and crystalline structures were formed . These structural modifications, which increased with culture age, were never observed in bacteria grown in control medium . Optical diffraction analysis of the crystalline structures in freeze-etched cells revealed regular periodic arrays with a rhomboid repeating unit approximately 7.6 x 5.4 nm in dimension and an angle between the axes of about 73 degrees . Negative staining of isolated membranes of bacteria grown in deficient medium showed a more complex organization of the crystalline arrays, each unit being clearly composed of subunits.

J Bacteriol, 1980 Jul, 143(1), 89 - 99
Positive correlation between size at initiation of chromosome replication in Escherichia coli and size at initiation of cell constriction; Koppes LJ et al.; The variability of (i) the length (size) at which cells initiate chromosome replication, (ii) the length at which they initiate cell constriction, and (iii) the time interval between these events has been estimated for Escherichia coli B/r K at two different slow growth rates . Steady-state cultures were pulse-labeled with {3H}thymidine and, after fixation, analyzed by electron microscopic radioautography . The coefficient of variation of length at initiation of chromosome replication was found to be 15 to 22%, the coefficient of variation of length at initiation of cell constriction was 10%, and the coefficient of variation of the time interval between both events was 25% . With the help of these values we calculated a high positive coefficient of correlation (rho) between the length at which a round of chromosome replication is initiated and that at which the onset of cell constriction occurs . At both growth rates rho has a value of 0.6 to 1.0 . This correlation excludes a model in which chromosome initiation and cell constriction are independently triggered by some aspects of cell growth . It favors a model in which an event before or at chromosome initiation triggers both.

J Bacteriol, 1980 Jul, 143(1), 538 - 9
Uptake of glycerol 3-phosphate and some of its analogs by the hexose phosphate transport system of Escherichia coli; Guth A et al.; The hexose phosphate transport system transported glycerol 3-phosphate and its analogs 3,4-dihydroxybutyl-1-phosphonate, glyceraldehyde 3-phosphate, and 3-hydroxy-4-oxobutyl-1-phosphonate.

J Bacteriol, 1980 Jul, 143(1), 535 - 7
Selective synthesis of plasmid-coded proteins by Escherichia coli during recovery from chloramphenicol treatment; Neidhardt FC et al.; Protein products of recombinant ColE1 plasmids are preferentially synthesized and can easily be identified in Escherichia coli cells recovering from prolonged treatment with chloramphenicol.

J Bacteriol, 1980 Jul, 143(1), 520 - 4
Dimer excision in Escherichia coli in the presence of caffeine; Rothman RH; The observation that polA1 and recL152 mutations result in both slow pyrimidine dimer excision and large repair patch size leads to the hypothesis that patch size is directly related to the rate of excision . In this study caffeine, a known inhibitor of excision repair, was used to examine the extent of correlation between excision rate and patch size by measuring patch size in the presence of several concentrations of caffeine . Both the rate of excision and the resistance to ultraviolet radiation were reduced with increasing concentrations of caffeine after irradiation . Caffeine also inhibited the rate at which incisions were made and prolonged the time required to rejoin the discontinuities . Patch size, however, was unaffected by caffeine treatment.

J Bacteriol, 1980 Jul, 143(1), 510 - 2
Identification of peptide-cross-linked trisdisaccharide peptide trimers in murein of Escherichia coli; Gmeiner J; Purified murein from Escherichia coli K-12 was degraded into disaccharide peptide fragments by endo-N-acetylmuramidase from Chalaropsis . About 5% of the total murein fragments were recovered as peptide-cross-linked trisdisaccharide peptide trimers.

J Bacteriol, 1980 Jul, 143(1), 506 - 9
lac Thiogalactoside transacetylase of Escherichia coli K-12 and ML; Fried VA; The lac thiogalactoside transacetylase was purified from both a wild-type Escherichia coli K-12 strain (H3000) and an E . coli ML strain (ML308) . These enzymes are indistinguishable by using several criteria . The subunit molecular weight of the enzyme is 24,800, which is significantly less than the previously reported value of 30,000 . Although the function of the thiogalactoside transacetylase is unknown, it is suggested that this enzyme plays an important role in lactose utilization since its structure and enzymatic activity have been conserved.

J Bacteriol, 1980 Jul, 143(1), 455 - 62
Influence of chromosome integrity on Escherichia coli cell division; Markham BE et al.; The antitumor agent cis-platinum(II)diamminodichloride (PDD) caused wild-type and recA+ deoxyribonucleic acid (DNA) repair-deficient mutant cells of Escherichia coli K-12 to grow as long, multinucleated filaments . At 5 micrograms/ml, the times required for reduction of viability to 37% for wild-type, polA, recB,C, uvrA, and recA organisms were > 200, 200, 120, 25, and 5 min, respectively . Only recA cells exhibited @reckless" degradation of DNA at this concentration of PDD . As shown by sedimentation in alkaline sucrose gradients, generation of single-strand breaks in DNA of the remaining organisms was a major consequence of growth in PDD . Upon incubation in fresh medium after removal of the compound and storage for 4 h at 4 degrees C, a respective lag of 3, 4, 6, and 9 h occurred before filaments of wild-type, polA, recB,C, and uvrA cells commenced cell division . Maintenance at 4 degrees C, which evidently delayed postshift initiation of chromosome replication, was only essential for fragmentation of uvrA filaments . In all cases, these periods of division delay corresponded to those required for restoration of normal chromosomal molecular weight as determined in alkaline sucrose gradients.

J Bacteriol, 1980 Jul, 143(1), 396 - 402
Proton-linked D-xylose transport in Escherichia coli; Lam VM et al.; The addition of xylose to energy-depleted cells of Escherichia coli elicited an alkaline pH change which failed to appear in the presence of uncoupling agents . Accumulation of {14C}xylose by energy-replete cells was also inhibited by uncoupling agents, but not by fluoride or arsenate . Subcellular vesicles of E . coli accumulated {14C}xylose provided that ascorbate plus phenazine methosulfate were present for respiration, and this accumulation was inhibited by uncoupling agents or valinomycin . Therefore, the transport of xylose into E . coli appears to be energized by a proton-motive force, rather than by a phosphotransferase or directly energized mechanism . Its specificity for xylose as inducer and substrate and the genetic location of a xylose-H+ transport-negative mutation near mtl showed that the xylose-H+ system is distinct from other proton-linked sugar transport systems of E . coli.

J Bacteriol, 1980 Jul, 143(1), 383 - 8
Azaserine resistance in Escherichia coli: chromosomal location of multiple genes; Williams MV et al.; Resistance to azaserine in Escherichia coli is the result of mutations in at least three different loci . All spontaneously arising azaserine-resistant mutants harbor a lesion in the aroP gene . However, a lesion in this gene is not solely responsible for resistance . All spontaneously arising intermediate-level azaserine-resistant mutants also harbor a lesion in a gene designated azaA, which lies near min 43 on the chromosome . High-level resistant mutants harbor lesions in the aroP and azaA genes and in a third gene designated azaB, which lies near min 69 on the chromosome . Transport studies demonstrate that mutants harboring lesions in the azaA gene are not defective in the transport of the aromatic amino acids, but that mutants which harbor lesions in the azaB gene are defective in phenylalanine transport but not in tyrosine or tryptophan transport.

J Bacteriol, 1980 Jul, 143(1), 35 - 42
Hydroxamate-mediated transport of iron controlled by ColV plasmids; Stuart SJ et al.; A new high-affinity system for iron transport, associated with the presence of ColV plasmids, has been detected in Escherichia coli and partially characterized . The presence of such "iron-transport plasmids" in E . coli cells that are defective in enterochelin-mediated transport of iron enabled them to grow in media to which 2,2'-dipyridyl had been added to reduce availability of iron . In addition, the presence of plasmid deoxyribonucleic acid in a mutant defective in enterochelin biosynthesis was associated with a marked increase in the rate of radioactive-iron uptake . Plasmid-determined uptake of iron was distinct from previously recognized systems for iron transport in E . coli K-12, and the colicin V molecule appeared not to be directly involved . Hydroxylamine-nitrogen could be detected in cell pellets of ColV+ cultures, and similar material was detected in supernatant fluids of late log- or stationary-phase cultures . The hydroxamate material was not detected in cell pellets or culture supernatants of strains from which plasmids had been eliminated, and a 95% decrease in hydroxamate synthesis was observed when cells were grown in minimal medium containing 2 microM iron.

J Bacteriol, 1980 Jul, 143(1), 302 - 6
Catabolism of 3- and 4-hydroxyphenylacetate by the 3,4-dihydroxyphenylacetate pathway in Escherichia coli; Cooper RA et al.; Various strains of Escherichia coli (but not strain K-12) were found to grow on 3-hydroxyphenylacetate and 4-hydroxyphenylacetate . Both compounds were catabolized by the same pathway, with 3,4-dihydroxyphenylacetate as a substrate for fission of the benzene nucleus, and with pyruvate and succinate as products . All the necessay enzymes were demonstrated in cell extracts prepared from induced cells but were essentially absent from uninduced cells . Mutants unable to grow on 3- and 4-hydroxyphenylactetate were defective in particular enzymes of the pathway . The characteristics of certain mutants indicated that either uptake or hydroxylation of 3- and 4-hydroxyphenylacetate may involve a common protein component . E . coli also grew on 3,4-hydroxyphenylacetate, with induction of the enzyme necessary for its degradation but not those for the uptake-hydroxylation of 3- and 4-hydroxyphenylacetate.

J Bacteriol, 1980 Jul, 143(1), 231 - 7
Subunits of succinyl-coenzyme A synthetase: coordination of production in Escherichia coli and discovery of a factor that precludes refolding; Wolodko WT et al.; Succinyl-coenzyme A synthetase of Escherichia coli has an alpha 2 beta 2 subunit structure . By measuring reconstituted enzyme activity present after addition of purified alpha or beta subunits to cell extracts followed by refolding, we have shown that extracts contain no significant excess of either subunit species . This equivalence suggests that the expression of the respective structural genes for the subunits is coordinately controlled . The presence of cell extract does not affect the rate or extent of reassembly of the subunits, pointing to a high degree of specificity of mutual recognition by the refolding subunits . In the course of these experiments, we have detected the presence in cell extracts of a low-molecular-weight factor that specifically inactivates unfolded alpha or beta subunits or prevents their reassembly into catalytically active enzyme . Under conditions where the subunits are completely inactivated, the factor has no detectable effect on native or refolded tetrameric enzyme, suggesting that the factor may react only with unfolded protein.

J Bacteriol, 1980 Jul, 143(1), 212 - 20
Involvement of genes uvrD and recB in separate mutagenic deoxyribonucleic acid repair pathways in Escherichia coli K-12 uvrB5 and B/r uvrA155; Sargentini NJ et al.; We compared the ultraviolet radiation-induced reversion of nonsense (lacZ53) and missense (leuB19) mutations in uvrB5, uvrB5 uvrD3, uvrB5 recB21, and uvrB5 uvrD3 recB21 strains of Escherichia coli K-12 . Nonsense (trpE65) reversion was also compared in similar derivatives of E . coli B/r uvrA155 . The uvrD mutation reduced mutagenesis in very case, but had its main effect in cells ultraviolet irradiated with low fluences (< 0.6 J m-2) . The effect of the recB mutation varied; it decreased Leu and Trp reversion, but had little effect on Lac reversion . The effect of the uvrD recB combination was a gross reduction in mutagenesis . Only in the case of Lac reversion was appreciable mutagenesis detected (at fluences > 0.3 J m-2) . These results indicate that separate uvrD- and recB-controlled pathways exist for ultraviolet radiation mutagenesis.

J Bacteriol, 1980 Jul, 143(1), 158 - 67
Plasmids coding for heat-labile enterotoxin production isolated from Escherichia coli O78: comparison of properties; McConnell MM et al.; Nineteen enterotoxigenic Escherichia coli strains of serogroup O78, isolated in different geographical areas from humans with diarrheal diseases, were tested for their ability to transfer enterotoxin production . All of the strains originally produced heat-labile enterotoxin, and 16 also produced heat-stable enterotoxin and colonization factor antigen I . Plasmids coding for the production of heat-labile enterotoxin only were transferred from 13 strains . Some properties of these plasmids were compared . All were fi+, but they could be divided into three groups on the basis of their incompatibility reactions, ability to restrict E . coli K-12 phages, and size . The three heat-labile enterotoxin plasmids isolated from African strains all belonged to one enterotoxin plasmid group . The heat-labile enterotoxin plasmids from the Asian strains were divided into two groups, those from serotype O78.H11 differing from those from serotype O78.H12.

J Bacteriol, 1980 Jul, 143(1), 151 - 7
Outer membrane protein e of Escherichia coli K-12 is co-regulated with alkaline phosphatase; Tommassen J et al.; Outer membrane protein e is induced in wild-type cells, just like alkaline phosphatase and some other periplasmic proteins, by growth under phosphatase limitation . nmpA and nmpB mutants, which synthesize protein e constitutively, are shown also to produce the periplasmic enzyme alkaline phosphatase constitutively . Alternatively, individual phoS, phoT, and phoR mutants as well as pit pst double mutants, all of which are known to produce alkaline phosphatase constitutively, were found to be constitutive for protein e . Also, the periplasmic space of most nmpA mutants and of all nmpB mutants grown in excess phosphate was found to contain, in addition to alkaline phosphatase, at least two new proteins, a phenomenon known for individual phoT and phoR mutants as well as for pit pst double mutants . The other nmpA mutants as well as phoS mutants lacked one of these extra periplasmic proteins, namely the phosphate-binding protein . From these data and from the known positions of the mentioned genes on the chromosomal map, it is concluded that nmpB mutants are identical to phoR mutants . Moreover, some nmpA mutants were shown to be identical to phoS mutants, whereas other nmpA mutants are likely to contain mutations in one of the genes phoS, phoT, or pst.

J Bacteriol, 1980 Jul, 143(1), 100 - 4
Initiation of deoxyribonucleic acid replication in Escherichia coli B: uncoupling from mass/deoxyribonucleic acid ratio; Grossman N et al.; In Escherichia coli growing at different rates, the ratio of cell mass to the number of chromosome origins tended to be constant at the time of the initiation of deoxyribonucleic acid (DNA) replication . This observation led to the assumption that the initiation event is controlled in some way by cell mass, e.g., by a growth-dependent synthesis of an initiator or dilution of a repressor . We have now found that the initiation of DNA synthesis can be uncoupled from cell mass . We used a synchronous culture of newly divided cells of E . coli B which was obtained by the membrane elution technique (C.E . Helmstetter, J . Mol . Biol . 24: 417-427, 1967) and was starved for an amino acid . Upon restoration of the amino acid, the cells not only divided at a size that was smaller than normal, but also initiated DNA replication long before they could increase their masses to reach the expected ratio of mass/DNA presumably required for initiation.

J Bacteriol, 1980 Jul, 143(1), 1 - 7
Isolation and characterization of an Escherichia coli K-12 mutant defective in tyrosine- and phenylalanine-specific transport systems; Whipp MJ et al.; A mutant strain of Escherichia coli K-12 that is defective in both the tyrosine-specific and phenylalanine-specific transport systems was isolated . The defects in these systems were shown to be due to mutations in two distinct loci, tyrP and pheP, respectively.

Infect Immun, 1980 Jul, 29(1), 8 - 12
Role of complement in chemotaxis: study of a localized infection; Wilson DM et al.; A model of Escherichia coli-induced pyelonephritis was used to study the effect of complement depletion in an organ-specific, nonimmunological inflammatory lesion in rats . In this model of a local infection, which can be considered to be nonspecific inflammatory stimulus, the depletion of complement by the administration of a purified cobra venom factor did not alter the course of the disease . There were minor differences when the results from complement-depleted and normocomplementemic animals were compared, but the composition of the inflammatory infiltrate was not greatly altered . Therefore, the presence of C3 and a functional complement system are relatively unimportant factors in determining the characteristics of the inflammatory response in a localized infection-induced lesion.

Infect Immun, 1980 Jul, 29(1), 200 - 6
Comparative analysis of plasmids and some metabolic characteristics of Escherichia coli K1 from diseased and healthy individuals; Silver RP et al.; All 62 Escherichia coli strains possessing the K1 capsular polysaccharide contained plasmid deoxyribonucleic acid, and most (51 of 62) had multiple plasmid species . The incidence of hemolysins, colicins, hemagglutinins for human erythrocytes, and plasmids did not differ among K1 strains isolated from the cerebrospinal fluids of neonates with meningitis or among those strains isolated from the stools of healthy individuals of all ages . There was an association between E . coli serotype and the distribution of plasmids, hemolysins, and colicins among the K1 strains . A common plasmid of about 65 megadaltons was found in all of the O18 serotypes; the similarity of these plasmids was confirmed by analysis with the restriction endonuclease EcoRI . Plasmids of similar molecular weight were also present in E . coli strains of the O7:K1 and O75:K100 serogroups . These data are consistent with the hypothesis that E . coli strains of the same serotype may be descendents of a single bacterial clone.

Infect Immun, 1980 Jul, 29(1), 108 - 13
Detection of Escherichia coli enterotoxins in stools; Merson MH et al.; We determined whether enterotoxigenic Escherichia coli diarrhea could be diagnosed by direct examination of stools for heat-labile (LT) and heat-stable (ST) enterotoxins . The Y-1 adrenal cell and an enzyme-linked immunosorbent assay (ELISA) detected LT in 85 and 93%, respectively, of stool specimens obtained from adults with acute diarrhea from whom an LT- and ST-producing organism had been isolated . Furthermore, the ELISA assay detected LT in 8 of 35 stool specimens from which no LT-producing E . coli had been isolated . The infant mouse assay was utilized to detect ST in these stool specimens and was found to be an insensitive method, showing positive results in only 36% of the specimens from which an ST-producing organism was isolated . Further studies are warranted to determine the diagnostic value of direct detection of LT in stools, especially by the ELISA method.

Cancer Res, 1980 Jul, 40(7), 2455 - 60
Effects of arsenic, selenium, and chromium on the fidelity of DNA synthesis; Tkeshelashvili LK et al.; The effect of three environmentally important metals, arsenic, selenium, and chromium, on the accuracy of DNA synthesis in vitro has been analyzed . The addition of arsenic to fidelity assays did not significantly alter accuracy . Selenium did not alter fidelity under normal conditions of magnesium activation, nor did it affect the mutagenicity of manganese . Chromium in the form of Cr(III) as well as Cr(VI) diminished the fidelity by which Escherichia coli DNA polymerase I copies polynucleotide templates . Nearest-neighbor analysis of the product synthesized in the presence of chromium indicates that the misincorporated in the presence of chromium indicates that the misincorporated bases are present as single-base substitutions . Chromium was also mutagenic using the recently developed phi chi 174 assay, which measures the fidelity of DNA synthesis with a natural DNA template.

Radiology, 1980 Jul, 136(1), 33 - 42
Renal parenchymal malacoplakia; Hartman DS et al.; Malacoplakia is a rare inflammatory disease which usually involves the bladder and only rarely affects the renal parenchyma . The clinical, radiographic, and pathological findings in 5 cases of renal parenchymal malacoplakia (RPM) are presented and 30 cases from the literature are reviewed . Most patients are middle-aged women with E . coli pyelonephritis . Radiographically, two patterns of involvement are recognized: multifocal and unifocal . The prognosis depends on the pattern and extent of RPM; long-term survival is possible with appropriate therapy.

Diabetes, 1980 Jul, 29(7), 528 - 31
L-Asparaginase-induced diabetes mellitus in rabbits; Lavine RL et al.; Twenty-seven male New Zealand White rabbits were injected with a single dose of 10,000 IU E . coli L-asparaginase per kilogram body wt to document the diabetogenic activity of this antitumor agent . Significant weight loss was observed by day 1, and a loss continued until day 9 . After day 16, weight steadily increased . Random serum glucose levels increased steadily after the injection of L-asparaginase, reaching a peak value of 344 +/- 32 mg/dl (x- +/- SEM) on day 10 . From day 12, levels declined, but they remained significantly higher than basal levels . Serum immunoreactive insulin (IRI) levels had a similar pattern of response . By day 2 the IRI was significantly above baseline . The IRI levels increased daily, reaching a peak level of 1,379 +/- 587 pg/ml (x- +/- SEM) . Thereafter the levels fell gradually . However, the IRI levels remained significantly higher than basal levels . Intravenous regular insulin decreased glucose levels in L-asparaginase-treated animals at 3 h by only 7.7 +/- 3.2%, while it decreased them in controls by 34.0 +/- 6.7% (P less than 0.0025) . These data demonstrate that, acutely, a single intravenous dose of 10,000 IU E . coli L-asparaginase per kilogram body wt induces a hyperinsulinemic . Insulin-resistant, diabetic syndrome in rabbits.

Ann Immunol (Paris), 1980 Jul-Aug, 131D(1), 71 - 8
{A colorimetric method for the evaluation of phagocytosis by mouse peritoneal macrophages (author's transl)}; Raichvarg D et al.; In this study, a technique for the evaluation of circulating leukocyte phagocytosis has been adapted to mouse peritoneal macrophages . This quantitative determination was performed by the spectrophotometric measurement of the reduced nitroblue tetrazolium (NBT) fixed on bacteria or latex spherules . Capacity of phagocytosis was thus correlated with the intensity of the NBT intracellular reduction by macrophages . This method is technically simple and requires no expensive materials . The phagocytosis of latex did not significantly differ, neither in the presence of autologous or heterologous serum (X +/- G = 0.100 +/- 0.014/2.5 X 10(6) cells) nor in the absence of serum (X +/- G = 0.088 +/- 0.007/2.5 X 10(6) cells) . The use of macrophages suspended in the culture medium highly decreased the phagocytic activity (X +/- G = 0.021 +/- 0.002/2.5 X 10(6) cells) and confirmed thus the role played by the support in endocytosis . A specific antiserum weakly enhanced the phagocytic process for Escherichia coli . The mean values with and without serum were 0.065 +/- 0.005/2.5 X 10(6) cells and 0.050 +/- 0.005, respectively . Heating of the serum (56 degrees C, 30 min) and inhibition of both complement activation pathways by EDTA showed that complement plays the major role in this weak enhancement of bacterial phagocytosis by peritoneal mouse macrophages . Bacterial phagocytic stimulation of macrophages was not induced by addition of CA+++ or Mg++ into the culture medium.

Mech Ageing Dev, 1980 Jul, 13(3), 247 - 52
Error propagation in Escherichia coli and its relation to cellular ageing; Rosenberger RF et al.; The mistranslation of alkaline phosphatase may not provide a definitive measure of errors in Escherichia coli protein synthesis . beta-Galactosidase which, unlike alkaline phosphatase, is an intracellular enzyme exhibits different mistranslation kinetics . Previous conclusions based on alkaline phosphatase data and showing no relation between error propagation and ageing may require re-evaluation.

Am J Epidemiol, 1980 Jul, 112(1), 17 - 22
The risk of acquiring hepatitis from sewage-contaminated water; Rosenberg ML et al.; There is little information on the risk of acquiring hepatitis A from drinking sewage-contaminated water . In a large outbreak of gastrointestinal illness at Crater Lake National Park, Oregon, a US national park, in June-July, 1975, approximately 100,000 persons were exposed to sewage-contaminated water . State health departments reported three cases of Crater Lake-associated hepatitis A for a rate of 12/100,000 per year, comparable to the reported US incidence of non-B hepatitis 10/100,000 per year . Questionnaire survey of 3997 overnight park visitors revealed five cases of hepatitis A, occurring in 2206 persons who drank water but did not receive immune serum globulin (ISG) within two weeks of exposure, an attack rate of 0.23% . The association between drinking park water and subsequently developing hepatitis was not statistically significant . No cases of hepatitis occurred in 320 park staff and family members, repeatedly exposed to contaminated water . The authors do not recommend routine use of prophylactic ISG for similar outbreaks of gastroenteritis caused by sewage-contaminated water but suggest close surveillance of the exposed group, and careful consideration of risk factors and costs.

Biokhimiia, 1980 Jul, 45(7), 1274 - 83
{Nature of membrane ATPase inactivation in an Escherichia coli mutant with genetically impaired ATPase}; Chetkauskaite AV et al.; Homogeneous preparations of F1 possessing identical subunit composition have been isolated from the mutant strain of E . coli AN 120 with genetically impaired membrane ATPase and from the wild strain of AN 180 . Using ion-exchange chromatography, the subunits alpha and beta of F1 were isolated . It was shown that the alpha- and beta-subunits of both active and genetically impaired F1 have similar molecular weights and total electrical charges.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3962 - 6
Initiation of genetic recombination: homologous pairing between duplex DNA molecules promoted by recA protein; Cassuto E et al.; recA protein has been shown to promote hydrogen bonding between single-stranded DNA fragments and duplex DNA molecules homologous to them . However, genetic and biochemical evidence indicates that genetic exchanges generally take place between duplex molecules . We therefore chose to study the interactions promoted by recA protein between intact duplex DNA molecules and molecules containing gaps that are believed to increase the frequency of genetic exchanges . In the present paper, we show that incubation of intact and gap-containing plasmid DNA in the presence of recA protein leads to homologous pairing between duplex molecules which can be detected by centrifugation analysis and electron microscopy . The reaction is completely dependent on an active recA gene product, on genetic homology between the DNA species involved, and on the presence of ATP; under certain conditions, its efficiency can be increased considerably by the presence of the single-stranded DNA binding protein of Escherichia coli.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3932 - 6
Structure of a cloned circular Moloney murine leukemia virus DNA molecule containing an inverted segment: implications for retrovirus integration; Shoemaker C et al.; Closed circular Moloney murine leukemia virus (M-MuLV) DNA was prepared from recently infected cells and cloned in a lambda vector . Four classes of cloned M-MuLV inserts were found: Class I, full length 8.8-kilobase (kb) inserts with two tandem long terminal repeats (LTRs) of 600 base pairs; class 2, 8.2-kb inserts with a single copy of a LTR; class 3, M-MuLV DNA inserts with various portions deleted; and class 4, an 8.8-kb insert with an internal sequence inversion . Determination of nucleotide sequence at the junction between the two LTRs from a class 1 insert suggested that circularization occurred by blunt-end ligation of an 8.8-kb linear DNA . The class 4 molecule had an inversion that was flanked by inverted LTRs, each of which had lost two terminal base pairs at the inversion end points . Also, four base pairs that were present only once in standard M-MuLV DNA were duplicated at either end of the inversion . This molecule was interpreted as resulting from an integrative inversion in which M-MuLV DNA has integrated into itself . Its analysis thus provided explicit information concerning the mechanism by which retrovirus DNA integrates into host cell DNA . Models of retrovirus integration based on bacterial DNA transposition mechanisms are proposed.

Mol Biol (Mosk), 1980 Jul-Aug, 14(4), 867 - 80
{Radioimmunoanalytic study of the kinetics of lambda phage structural protein synthesis}; Ivanov VN et al.; The kinetics of the lambda-phage major structural protein syntheses was determined during the lytic development by radioimmunoassay . For this purpose, the individual structural proteins such as pE, pV and pD were isolated in polyacrylamide gel by the preparative SDS-electrophoresis . The proper monospecific antisera were obtained . All the proteins were labelled with 125J in vitro by a chloramine method . The degree of nativity for iodinated proteins was determined by the electrophoretic and immunochemical methods . The concentrations of proteins pE, pV and pD were measured in lysates of E . coli W3350 cells infected with the phage lambda C1857 at various time intervals after infection using a competitive radioimmunoassay . The concentrations of all three proteins turned out to increase sharply between 20 and 40 minutes after infection, then the rate of synthesis of structual proteins declined gradually . On a cell basis the accumulation of major proteins of the head such as pE and pD exceeded by a factor of 10 or 20 the amount required for collection of the infected progeny or pahge; at the same time the primary component of the tail pV accumulated to a lesser extent . The autonomic regulation of the syntheses of major phage proteins is assumed to be exercised as a translation level in the lytic development of the phage lambda.

J Antibiot (Tokyo), 1980 Jul, 33(7), 744 - 50
The biological effect of a nonprotein component removed from neocarzinostatin (NCS); Ohtsuki K et al.; The biological effects of both nonprotein component (NPC) and PC (protein component) from NCS have been studied in vivo and in vitro . NPC was found to not only inhibit DNA synthesis in growing cells but also induce DNA degradation in vivo and in vitro . However, neither these two biological activities of PC were detected even at a 100-times higher concentration of NPC (0.2 micrograms/ml) which inhibited 50% DNA synthesis in growing cells . NPC-induced DNA degradation in vitro was stimulated by 2-mercaptoethanol as has been reported for NCS . These results show that the NPC removed from NCS is responsible for the biological activities such as the inhibition of DNA synthesis in growing cells and the induction of DNA degradation in vivo and in vitro.

Vopr Med Khim, 1980 Jul-Aug, 26(4), 568 - 72
{New means of isolating restriction endonuclease preparations using organic solvents}; Sokolov NN et al.; A new procedure is developed for isolation of highly purified preparations of restrictional endonoucleases Bam HI and Eco RI by means of fractionation with isopropyl alcohol . Restrictional endonuclease Bam HI, practically free of unspecific nucleases, was isolated after ultrasonic destruction of cells, precipitation of the restrictases with isopropanol and chromatography on DEAE cellulose . Additional chromatography on hydroxyapatite enabled to obtain the homogenous preparation of Bam HI restrictase, as shown by polyacrylamide gel disc electrophoresis . Other organic solvents (acetone, ethanol) might be also used for purification of the restrictional endonucleases.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 4201 - 5
Cloning of reiterated and nonreiterated herpes simplex virus 1 sequences as BamHI fragments; Post LE et al.; Over 95% of the herpes simplex virus type 1 (strain F) DNA sequences have been cloned as BamHI fragments in the pBR322 plasmid . With one exception, all of the cloned fragments have the same electrophoretic mobilities and restriction enzyme cleavage sites as do the authentic fragments derived from the BamHI digests of the viral genome . The exception is the BamHI B fragment mapping at the right end of L component in the prototype arrangement of the DNA . Thus, a small deletion mapping near the left end of the fragment was present in two independently derived plasmids . Included in the collection of plasmids are several clones containing DNA sequences that span the junction between the L and S components of the virus DNA . Several plasmids containing the junction fragment were found to be sufficiently stable to permit the preparation of large amounts of the DNA fragment for fine-structure mapping of the restriction enzyme cleavage sites . Preliminary studies on one cloned fragment (BamHI G) have shown that it is biologically active in marker rescue of a temperature-sensitive mutation and in transfer of a plaque morphology marker.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3978 - 82
Transformation of rat embryo fibroblasts by cloned polyoma virus DNA fragments containing only part of the early region; Hassell JA et al.; Recombinant plasmids containing either the entire polyoma viral genome or one or the other of the two HindIII fragments of polyoma virus DNA were constructed and cloned in Escherichia coli X1776, and their DNAs were individually tested for the capacity to transform an established line of rat cells . The recombinant plasmids containing the entire polyoma genome and those containing the HindIII-1 fragment of polyoma DNA (45-1.4 map units) efficiently transform rat cells, whereas the plasmids containing the HindIII-2 fragment (1.4-45.0 map units) do not . The properties of many independent transformed cell lines established by infection with the cloned HindIII-1 fragment were determined . In contrast to the parent cell line, rat cells transformed with the cloned HindIII-1 fragment grow to high saturation densities, form colonies with high efficiency in dilute agar suspension, produce high levels of plasminogen activator, and display a disorganized arrangement of actin cables . By all criteria examined, these cells transformed by fragments are indistinguishable from cells transformed by whole polyoma viral DNA . Cellular DNA prepared from many HindIII-1 fragment-transformed cell lines was analyzed for the presence and arrangement of polyoma viral sequences by Southern blot-hybridization . In all cases examined, only those viral sequences contained within the HindIII-1 fragment of polyoma DNA were detected . These data establish a strong correlation between polyoma DNA sequences mapping within a restricted portion of the early region and the induction and maintenance of the transformed phenotype.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3879 - 83
Involvement of cyclic GMP in intracellular signaling in the chemotactic response of Escherichia coli; Black RA et al.; The intracellular signal that produces changes in swimming behavior when bacteria encounter attractants or repellents has not previously been identified . We suggest, based on the following lines of evidence, that cyclic GMP (cGMP) is involved in this signaling process in chemotaxis by Escherichia coli . (i) The addition of attractants to bacteria causes a transient increase in the intracellular level of cGMP, whereas a repellent stimulus decreases the level transiently . These changes do not generally occur in a mutant lacking chemotaxis-specific proteins . (ii) In the absence of chemoeffectors, both addition of cGMP to bacteria and reducing the intracellular cGMP level produce changes in swimming behavior, and a mutant with an abnormal swimming pattern has an altered intracellular cGMP level . (iii) cGMP modulates the demethylation reaction responsible for adaptation to stimuli . (iv) Mutants defective in components of the adaptation system have altered cGMP metabolism.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3865 - 9
Deletions covering the putative promoter region of early mRNAs of simian virus 40 do not abolish T-antigen expression; Benoist C et al.; A recombinant plasmid was constructed by insertion of the early genes of simian virus 40 (SV40) into pBR322 . When it was introduced into eukaryotic cells, the SV40 early genes were expressed . We have made deletion mutants of this plasmid, from which the major cap sites of SV40 early mRNAs have been removed along with some of the sequences upstream . The deleted sequences appear to be dispensable for early gene expression, but this does not necessarily imply that they serve no function in the initiation of transcription on wild-type SV40.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3860 - 4
Cloning and mapping of BamHi endonuclease fragments of DNA from the transforming B95-8 strain of Epstein-Barr virus; Skare J et al.; DNA from the B95-8 strain of Epstein-Barr virus was cleaved into 29 different fragments by BamHI endonuclease (EC 3.1.23.6) . All of the fragments except the terminal fragments have been inserted into the pBR322 cloning vector and replicated in Escherichia coli . The location of each cloned DNA fragment in the viral genome has been determined, providing a more detailed physical map of the genome than has been available previously.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 3778 - 82
Predicted structure of two adenovirus tumor antigens; Perricaudet M et al.; Early adenovirus type 2(Ad2) mRNA sequences have been cloned by using the pBR322 plasmid as a vector . Two clones that include sequences from region E1B were identified and their DNAs were characterized by hybridization, restriction enzyme cleavage, and DNA sequence analysis . The results showed that the clones were derived from two different spliced mRNAs . By combining our results with the established DNA sequence for region E1B of the closely related adenovirus type 5{Maat, J., van Beveren, C.P . & van Ormondt, H . (1980) Gene, in press} it was possible to deduce the structure of a 13S and a 22S mRNA . The two mRNAs differ from each other by the size of their intervening sequences . If translation starts at the first AUG following the cap, the 22S mRNA encodes a Mr 67,000 polypeptide that is terminated by a UGA stop codon located immediately before the splice, whereas the 13S mRNA encodes a Mr 20,000 polypeptide that is translated in different reading frames before and after the splice . The Mr 20,000 and 67,000 polypeptides correspond in molecular weight to two proteins that invariably are precipitated from infected cell extracts by antisera from animals carrying adenovirus-induced tumors.

J Cell Biol, 1980 Jul, 86(1), 327 - 9
Three-dimensional crystals of an integral membrane protein: an initial x-ray analysis; Garavito RM et al.; Matrix protein, a pore-forming transmembrane protein spanning the outer membrane of Escherichia coli, has been obtained in a variety of three-dimensional crystal forms amenable to both electron microscope and x-ray analyses . Successful association into large crystals depended on the use of alpha-octyl glucoside, a detergent with relatively low affinity for the protein . Electron micrographs of thin-sectioned crystals show a high degree of order . Preliminary crystallographic data suggest that the crystals, which exhibit diffraction to 3.8 A, have a cubic space group.

J Virol, 1980 Jul, 35(1), 76 - 92
Functional organization of the Harvey murine sarcoma virus genome; Chang EH et al.; The comparative infectivity of Harvey murine sarcoma virus (Ha-MuSV) DNA for NIH 3T3 cells was determined for supercoiled Ha-MuSV DNA molecularly cloned in lambda phage and pBR322 at its unique EcoRI site (which is located near the middle of the 6-kilobase pair {kbp} unintegrated linear viral DNA) and for two cloned subgenomic fragments: one was 3.8 kbp and lacked about 1 kbp from each side of the EcoRI site, and the second did not contain the 3 kbp of the unintegrated linear viral DNA located on the 3' side of the EcoRI site . Each subgenomic DNA induced foci of transformed cells, but with a lower relative efficiency then genomic DNA . Transfection with intact vector Ha-MuSV DNA yielded results similar to those obtained after separation of Ha-MuSV DNA from vector DNA . Cells lines were then derived from individual foci transformed with each type of viral DNA . Focus-forming virus was recovered from transformed cells after superinfection with a helper-independent virus, but the efficiency varied by several orders of magnitude . For several transformed lines, the efficiency of recovery of focus-forming virus was correlated with the structure of the Ha-MuSV DNA in the cells before superinfection . When 32P-labeled Ha-MuSV DNA probes specific for sequences on either the 3' or 5' side of the EcoRI site were used to analyze the viral RNA in the transformed cell lines, all lines were found to hybridize with the 5' probe, but some lines did not hybridize with the 3' probe . The transformed lines contained high levels of the Ha-MuSV-coded p21 or its associated GDP-binding activity . We conclude that the transforming region and the sequences that code for the viral p21 protein are both located within the 2 kilobases closest to the 5' end of the Ha-MuSV genome.

J Gen Microbiol, 1980 Jul, 119(1), 31 - 4
Isolation of Escherichia coli mutants (cpdB) deficient in periplasmic 2':3'-cyclic phosphodiesterase and genetic mapping of the cpdB locus; Beacham IR et al.; Mutants of Escherichia coli deficient in the periplasmic enzyme 2':3'-cyclic phosphodiesterase have been obtained . The gene, designated cpdB, was mapped by conjugation and transduction and found to be located about 0 . 11 min to the right of the cycA locus on the E . coli genetic map.

J Gen Microbiol, 1980 Jul, 119(1), 231 - 8
DNA restriction and modification in Escherichia coli: functional analysis of the role of the dnaC(D) gene product; Hubacek J et al.; Escherichia coli strain PC-7 carries two independent temperature-sensitive mutations, one affecting the restriction and modification (R-M) phenotype and the other the DnaC(D) phenotype . The results of complementation and P1 transduction analysis of the mutation affecting the R-M phenotype implicate a fourth gene, designated hsdX, located close to the hsd three-gene complex . The properties of merodiploids constructed between appropriate recipients and F' elements with different mutations in hsdS, hsdR and hsdM genes might indicate that in strain PC-7 the temperature-sensitive products, determined by hsdR and hsdSK cistrons, are synthesized . The role of the temperature-sensitive dnaC(D) gene product in the formation of the restriction endonuclease was studied and no direct relation was found between the DnaC(D) and R-M phenotypes.

J Bacteriol, 1980 Jul, 143(1), 529 - 30
Construction of an Hfr strain useful for transferring recA mutations between Escherichia coli strains; Csonka LN et al.; Strain JC10240 (Hfr PO45 srlC300::Tn10 recA56 thr-300 ilv-318 rpsE300) was constructed . On account of the close linkage of Tn10 to recA56, the latter can be moved to other Escherichia coli (and closely related) strains in transductional or conjugational crosses selecting resistance to tetracycline.

J Bacteriol, 1980 Jul, 143(1), 513 - 5
Regulation of aspartokinase III synthesis in Escherichia coli: isolation of mutants containing lysC-lac fusions; Richaud F et al.; Mutants containing fusions of the lac gene to the lysC gene were isolated . In these, the expression of beta-galactosidase was regulated by lysine (and arginine), as previously described for aspartokinase III.

Infect Immun, 1980 Jul, 29(1), 140 - 3
Transfer of a CFA/I-ST plasmid promoted by a conjugative plasmid in a strain of Escherichia coli of serotype O128ac:H12; Reis MH et al.; Escherichia coli strains belonging to serotype O128ac:H12 and producing heat-stable enterotoxin (ST) and colonization factor CFA/I were found in Sao Paulo in children with diarrhea, but not in normal children . Segregants occurred in such strains with a frequency of about 10%, which have lost the ability to produce ST and CFA/I at the same time . From one strain, both properties were transformed jointly in matings to an E . coli K-12 strain . All such ST+ CFA/I+ progeny had received two plasmids of length 97 and 64 kilobases in the matings . Insertion of a transposon, Tn5, carrying a gene for kanamycin resistance, into the two plasmids enabled us to select for kanamycin-resistant progeny in further matings . Analysis of such progeny strains in terms of plasmid content and production of ST and CFA/I revealed that the larger plasmid carries the genes for St and CFA/I and is not self-transmissible, whereas the smaller plasmid does not carry any recognizable phenotypic traits, but is conjugative and promotes cotransfer of the larger plasmid with a frequency of about 30%.

Gene, 1980 Jul, 10(2), 95 - 103
Cloning and characterization of 4.5S and 5S RNA genes in tobacco chloroplasts; Takaiwa F et al.; Tobacco chloroplast 4.5S and 5S RNAs were shown to hybridize with a 0.9 . 10(6) dalton EcoRI fragment of tobacco chloroplast DNA . Recombinant plasmids were constructed from fragments produced by partial digestion of the chloroplast DNA with EcoRI and the pMB9 plasmid as a vector . Five recombinants containing the 4.5S and 5S genes were selected by the colony hybridization technique . One of these plasmids contained also the 16S and 23S RNA genes and was mapped using several restriction endonucleases as well as DNA-RNA hybridization . The order of rRNA genes is 16S-23S-4.5S-5S and the four rRNA genes are coded for by the same DNA strand.

Gene, 1980 Jul, 10(2), 177 - 83
3'-end labeling of DNA with {alpha-32P}cordycepin-5'-triphosphate; Tu CP et al.; Cordycepin-5'-triphosphate (3'-deoxyadenosine-5'-triphosphate) can be incorporated into the 3'-ends of DNA fragments using terminal deoxynucleotidyl transferase from calf thymus (Bollum, 1974) . Because cordycepin-5'-monophosphate lacks a 3'-OH group, only a single residue is incorporated . Furthermore, DNA molecules that contain cordycepin-5'-monophosphate at their 3'-ends become resistant to hydrolysis by exonucleases that require free 3'-OH ends . As an alternative to 5'-end labeling of complementary DNA strands, we have used {32P}cordycepin-5'-triphosphate labeling of 3'-ends to confirm the nucleotide sequence of a HhaI-endonuclease-generated pTU4-plasmid DNA fragment that contains several hot spots for insertions of the transposable genetic element Tn3 . 3'-End labeling with {32P} cordycepin-5'-triphosphate has also proved useful in determining the sequence of the pTU4 DNA in the vicinity of a strategically located SstII endonuclease cleavage site in the replication region of the plasmid.

Gene, 1980 Jul, 10(2), 157 - 66
Sequence of a yeast DNA fragment containing a chromosomal replicator and the TRP1 gene; Tschumper G et al.; The DNA sequence of a 1.45 kb EcoRI fragment from the yeast (Saccharomyces cerevisiae) TRP1 region has been determined . The fragment contains the TRP1 gene and a yeast chromosomal replicator . The TRP1 gene has been located on the fragment by analysis of potential initiation and termination codons in the DNA sequence . This location has been confirmed by subcloning portions of the fragment . Both the 5' and 3' noncoding regions of the TRP1 gene contain sequence homologies with analogous areas surrounding other yeast genes . The yeast replicator has been localized in a region near the 3' end of the TRP1 gene . The DNA sequence in this region contains several structural features which may be involved in the initiation of DNA replication.

Gene, 1980 Jul, 10(2), 147 - 55
Enrichment of specific genes from genomic DNA or from clone library DNA, using R-looping; Tyler BM et al.; We have developed a procedure for enriching DNA for specific sequences that is based on R-looping (Thomas et al., 1976) . R-loops are formed with the DNA using mRNAs containing the sequence of interest and then isolated on poly(U)-sepharose via the poly(A) tail of the mRNA . Model experiments showed that plasmid DNA containing a cDNA copy of an immunoglobulin kappa chain mRNA could be selectively retrieved using this procedure . Approx . 5-10% of the kappa sequences in mouse embryo DNA could be recovered by R-looping, while non-specific binding of mouse DNA to the poly(U)-sepharose column was 0.03-0.04% . This represents a 100-200-fold enrichment of mouse genomic kappa sequences . We have also used the procedure to rapidly screen a mouse clone library for immunoglobulin heavy chain genes . DNA from the clone library was enriched 100-200-fold using immunoglobulin heavy chain mRNAs, and the enriched DNA repackaged in vitro to recover the phage.

Proc Natl Acad Sci U S A, 1980 Jul, 77(7), 4003 - 6
Molecular cloning of human interferon cDNA; Taniguchi T et al.; A hybrid plasmid, TpIF319, has been shown to contain the sequence for human fibroblast interferon mRNA {Taniguchi, T., Sakai, M., Fujii-Kuriyama, Y., Muramatsu, M., Kobayashi, S . & Sudo, T . (1979) Proc . Jpn . Acad . 55, Ser . B, 464-469} . This conclusion was confirmed by a hybridization-translation assay, using rabbit globin mRNA and its cDNA-containing plasmid as a control . Plasmid TpIF319 was used as probe and another recombinant plasmid, TpIF319-13, whose cDNA insert consists of about 800 base pairs, was isolated . Nucleotide sequence analysis of the cDNA revealed that the DNA in fact codes for human fibroblast interferon.

Mol Biol (Mosk), 1980 Jul-Aug, 14(4), 939 - 50
{Isolation and physical study of the 13S fragment of 16S RNA and its complex with ribosomal protein S4}; Shpungin IL et al.; A fragment of E . coli 16S RNA has been obtained by its hydrolysis with pancreatic RNAase A coupled to Sepharose 4B . This fragment has a molecular weight of 170 000 and a sedimentation coefficient of 13S . It does not aggregate in solution and binds with the ribosomal protein S4 . The 13S fragment and it complex with the protein S4 have been studied by different physical methods in the first place, by neutron scattering . It has been shown that this fragment is compact in solution . The radii of gyration of the fragment (50 +/- 3 A) and of the protein S4 within the complex (17 +/- 3 A) coincide, within limits of experimental error, with the radii of gyration for the free RNA fragment (47 +/- 2 A) and the free ribosomal protein S4 in solution (18 +/- 2 A) . Hence, the conclusion is made that the compactness of the 13S fragment of the 16S RNA and the ribosomal protein S4 does not change at the complex formation . The compact 13S fragment of the 16S RNA is shown to be contrast matched in the H2O/D2O mixture containing 70% D2O which corresponds to its partial specific volume v equal to 0.537 cm3/g.

Mol Biol (Mosk), 1980 Jul-Aug, 14(4), 759 - 65
{Role of the beta-subunits of Escherichia coli RNA-polymerase in the regulation of gene activity}; Kamzolova SG et al.; The DNA-dependent RNA-polymerase from E . coli B/r and its rif-r mutant rpoB409 with pleiotropic effect has been studied . It was shown, that multiple forms of promotor sites in T4- and T7-DNA "early" regions are recognized with different efficiences by RNA-polymerases from E . coli B/r and rpoB409 . The rif-r rpoB409 mutation has been reported to affect the beta-subunit . Thus, the present data indicates that the selection of promoter sites can be controlled by the beta-subunit of RNA-polymerase.

Mol Biol (Mosk), 1980 Jul-Aug, 14(4), 734 - 42
{Formation of specific T3-RNA-polymerase complexes with oligoribonucleotides and inhibition of DNA-dependent RNA synthesis}; Efimova LIu et al.; It was shown previously that E . coli RNA polymerase and T7 RNA polymerase being incubated with oligonucleotides of different length derived from RNA endonuclease hydrolysate bind selectively to certain oligonucleotides with the length larger than or equal to 5 . The data presented demonstrate that T3 RNA polymerase also binds selectively from the isoplith mixtures certain oligonucleotides starting from pentanucleotides . Adding of excess of T3 RNA polymerase it was possible to exhaustively extract the recognizable oligonucleotides from the isoplith mixture . However, the exhausted by T3 RNA polymerase mixture of pentanucleotides still contained those which are bound selectively by T7 and E . coli RNA polymerases . The data suggest that various RNA-polymerases recognize different oligoribonucleotides . It was shown that T3 DNA inhibits the selective binding of penta-or heptaribonucleotides to T3 RNA polymerase competing obviously for the enzyme . The T3 RNA polymerase bound penta- or heptanucleotides inhibit DNA-dependent RNA synthesis carried out by the enzyme; the isoplith mixtures which do not contain T3 RNA polymerase bound oligonucleotides are deprived of the inhibitory properties . Only those isoplith mixtures contain T3 RNA polymerase bound oligonucleotides which were derived from symmetrically transcribed RNA which have obviously promoter simulating sequences . The data provide evidence that T2 RNA polymerase binds selectively the oligonucleotides mimicking the promotor recognition sites.

Eur J Biochem, 1980 Jul, 108(2), 423 - 31
Composition and properties of trypsin-cleaved elongation factor Tu; Wittinghofer A et al.; Native elongation factor Tu from Escherichia coli, EF-Tu, is initially attacked by trypsin at three adjacent sites in the primary structure . These are arginine-44, arginine-58, and lysine-56 . The rates of hydrolysis at the two arginine residues are about the same but that at the lysine residue is much slower . The products of the tryptic digestion have been analysed by Edman degradation and polyacrylamide gel electrophoresis . The peptide from alanine-45 to arginine-58 is eventually excised and does not complex with the remaining polypeptides (fragments A and D) . The loss of this peptide does not lead to a concomitant loss of activity in stimulating polyphenylalanine synthesis . The latter is closely correlated with the further hydrolysis of the remaining fragment (A + D) complex . This complex resembles native EF-Tu in its ability to stimulate both polyphenylalanine synthesis and the binding of aminoacyl-tRNA to 70-S ribosomes, but does not form so stable a ternary complex with aminoacyl-tRNA and GTP as the native protein.

J Bacteriol, 1980 Jul, 143(1), 285 - 92
Suppressors of a UGG missense mutation in Escherichia coli; Murgola EJ et al.; As part of our investigation of tRNA structure-function relationships, we isolated and preliminarily characterized translational suppressors of the tryptophan codon UGG in a trpA missense mutant of Escherichia coli . the parent strain also contained two other mutant alleles relevant to the suppressor search; these were supD, which codes for a serine-inserting amber suppressor tRNA, and gly V55, the gene for a GGA/G-reading mutationally altered glycine tRNA . On the basis of map location, reversed-phase (RPC-5) column chromatography of glycyl-tRNA, and codon response, several classes have been distinguished so far . The number of suppressors in each class, their codon responses, and their apparent genic identities, respectively, are as follows: class 1--4 suppressors, UGG, supD; class 2--12 suppressors, UGG, glyU; class 3--9 suppressors, UGA and UGG, glyT; class 4--2 suppressors, UGG, glyT; class 5--7 suppressors, UGG, gly V55 . Besides these, one suppressor retains supD activity, but so far its map location has not been distinguished from that of supD . Another suppressor clearly does not map near supD or any of the glycine tRNA genes mentioned . These last two suppressors may represent novel missense suppressors such as misacylated tRNA's or mutationally altered aminoacyl-tRNA synthetases, tRNA modification enzymes, or ribosomes . Finally, three other suppressors were obtained from a strain containing glyT56, the gene for an AGA/G-reading form of glyT tRNA . All three occurred at the expense of glyT56 activity and exhibited the the transductional linkage to argH that is characteristic of glyT.

Infect Immun, 1980 Jul, 29(1), 91 - 7
Properties of homogeneous heat-labile enterotoxin from Escherichia coli; Clements JD et al.; Recently, the heat-labile enterotoxin (LT) of Escherichia coli has been purified to homogeneity and partially characterized (Clements and Finkelstein, Infect . Immun . 24:760-769, 1979) . This study extends our observations on the physicochemical properties of LT . The toxin has an isoelectric point of pH 8.0, as compared with choleragen and choleragenoid, which have isoelectric points of pH 6.75 and 7.75, respectively . Sedimentation equilibrium measurements established an approximate molecular weight for LT of 91,440 . LT had an even more marked affinity than choleragen for agarose-containing matrixes in gel filtration . Of several mono- and disaccharides tested, only galactose and lactose were highly efficient in removing 125I-labeled LT from agarose-containing columns . LT dissociated into subunits (designated A and B) during gel filtration in the presence of 5 M guanidine . These subunits were immunologically distinct and possessed unique and shared antigenic determinants to the corresponding A and B subunits of choleragen . During gel filtration of LT at pH 6.5 and room temperature, a spontaneously occurring toxoid of LT, analogous to choleragenoid, was discovered and designated "coligenoid." This product contains only the B subunits of the toxin . A partial amino acid sequence of the B subunit of LT revealed a remarkable homology to the primary structure of cholera toxin B . Within the first 20 amino acids of the two chains, only 5 differ, and these differences may be attributable to single base substitutions.

Nord Vet Med, 1980 Jul-Aug, 32(7-8), 291 - 300
Summer mortality among caribou calves in West Greenland; Clausen B et al.; Colibacillosis with polyarthritis, due to E . coli O-group 55, has been found to be responsible for a high summer mortality among caribou valves in West Greenland . The mortality is presumably consequential on overstocking and therefore likely to subside as the caribou population in the preferred habitats is reduced to a lower density--the optimum level of which is as yet unknown.

J Gen Microbiol, 1980 Jul, 119(1), 87 - 93
Effects of temperature and energy inhibitors on complex formation between Escherichia coli male cells and filamentous phage fd; Yamamoto M et al.; The effect of temperature and various energy inhibitors on the formation of a complex between Escherichia coli male cells and filamentous phage fd was studied by a novel filtration method . Centrifuged male cells were observed by electron microscopy to have lost the majority of pili and to produce complexes with fd only above 25 degrees C . After preincubation of the cells at 37 degrees C without addition of the phage, nearly half the level of complex formation observed at 37 degrees C was detected at 0 degrees C and fd was at a minimum at about 20 degrees C . Several energy inhibitors and uncouplers drastically reduced complex formation at 37 degrees C, and also at 0 degrees C if the cells were briefly exposed to the reagents at the end of preincubation . Alteration of the cellular ATP concentration, either by shift-down of temperature or by the addition of the reagents, accompanied alteration in the ability of cells to form a complex with fd as well as alteration of the number of pili on the cell surface . In contrast to earlier reports, these results indicate that the complex formation between male cells and filamentous phage does not proceed either when pili disappear from the cell surface because of a decrease in the cellular energy level or when pili are removed by mechanical forces . The results also show that phage fd adsorption itself is not energy-dependent.

Biochim Biophys Acta, 1980 Jun 27, 608(1), 127 - 37
Physical properties of the complementary T4 RNA; Helland DE; The complementary transcribed T4 RNA after self-annealing and RNAase treatment was isolated by gel chromatography and then used for further studies . From salt-dependent RNAase resistance and melting studies it is evident that this RNA represents a genuine double-stranded structure . The base content of the isolated double-stranded RNA was found to be the same as total T4 mRNA . Sucrose gradient analysis and hydroxyapatite chromatography of T4 RNA, annealed early and late RNA, and of the isolated double-stranded RNA, gave results indicating that the complementary RNA is part of a RNA molecule and further that the size of the complementary regions are independent of the RNA molecules . Partial digestion of pulse-labelled late RNA with phosphodiesterase I prior to annealing with unlabelled early RNA, showed that the complementary regions on the mRNA are not located to the 5'- or 3'-end but randomly distributed along the T4 RNA molecules.

Biochim Biophys Acta, 1980 Jun 26, 623(2), 257 - 70
Interaction of calcium and calmodulin in the presence of sodium dodecyl sulfate; Burgess WH et al.; Calmodulin has been purified to homogeneity using an improved procedure that allows rapid processing of several kilograms of bovine brain . A calcium-dependent change in the electrophoretic mobility of calmodulin in the presence of sodium dodecyl sulfate (SDS) has been observed . Freshly prepared calmodulin or lyophilized calmodulin, stored at --80 degrees C for 1--7 months, migrates as a single band with an apparent molecular weight of 21 000 when the sample, gel and running buffer are made 0.1 mM in EDTA . When 0.1 mM CaCl2 is substituted for EDTA, freshly isolated calmodulin migrates as a single band with an apparent molecular weight of 15 000 . More slowly migrating bands, in addition to the 15 000 molecular weight band, are observed when the stored protein is electrophoresed under the same conditions . Calcium binding experiments show that freshly prepared calmodulin binds 4 mol of calcium per mol of protein in the presence of 0.1% SDS in 0.1 mM CaCl2 . Skeletal muscle troponin C, carp parvalbumin, and bovine brain S-100b do not show this mobility change . The calcium-dependent mobility change can be used to identify calmodulin in crude protein preparations . Calmodulin has been identified in the sperm of the sea urchin, Strongylocentrotus purpuratus, and purified . The urchin calmodulin activates cyclic nucleotide phosphodiesterase to the same extent as does brain calmodulin . We used several criteria to determine that calmodulin is not present as a soluble protein in Escherichia coli.

Biochim Biophys Acta, 1980 Jun 26, 623(2), 237 - 42
Mössbauer spectroscopy of Escherichia coli and its iron-storage protein; Bauminger ER et al.; 57Fe Mossbauer spectra of whole frozen Escherichia coli cells and of an iron storage protein isolated from iron-rich cells of E . coli have been measured over a range of temperatures down to 0.08 K . The spectra of E . coli cells with high iron content and of the iron storage protein were found to be very similar . Above 4 K these spectra consist of a quadrupole split doublet characteristic of Fe3+ . Below 3.5 K, the spectra display magnetic hyperfine splitting which is temperature dependent, and point to the existence of an ordered magnetic phase associated with a saturation magnetic hyperfine field of 43 tesla in both samples . The results indicate that the bulk of iron in the iron-rich cells is in the form of aggregates similar in nature to the iron cores in the isolated protein, although the latter account for not more than 1% of the total iron in the cells . The Mossbauer spectra of the isolated protein are different from those observed in ferritin, the iron-storage protein of plants and higher animals, showing that the iron cores in these two proteins are different.

Nucleic Acids Res, 1980 Jun 25, 8(12), 2835 - 42
Binding of meso-tetra (4-N-methylpyridyl) porphine to DNA; Fiel RJ et al.; The porphyrin photosensitizer, meso-Tetra (4-N-methyl-pyridyl) porphine tetraperchlorate is shown to unwind supercoiled ColEI DNA at a somewhat lower concentration than ethidium bromide . In contrast to this, the Fe(III) chelate of T4MPyP cannot unwind supercoiled DNA . It is concluded that these results corroborate our previous findings that, despite its large bulk, T4MPyP is fully capable of intercalating in DNA.

Nucleic Acids Res, 1980 Jun 25, 8(12), 2691 - 707
Molecular cloning of cDNA sequences coding for the major alpha- and beta-globin polypeptides of adult Xenopus laevis; Kay RM et al.; This report describes the synthesis and cloning of almost complete DNA copies of the mRNAs encoding the major alpha-globin and major beta-globin of X . laevis . Double-stranded globin cDNA was inserted into the PstI site of the plasmid pBR322 and two cloned recombinants (designated pXG6C1 and pXG8D2) were selected . These were shown to contain almost complete copies of X . laevis globin mRNA . Restriction enzyme maps were determined for each cDNA sequence using the established method of partial digestion of end labelled DNA . However, this procedure was modified such that isolation of individual DNA fragments was no longer required . Each plasmid was shown, by both hybrid arrested translation and filter selection of complementary RNA, to contain a sequence coding for one or other of the two major globin polypeptides . Sufficient DNA sequence information has been determined from each cDNA clone to demonstrate that pXG8D2 contains a beta-globin sequence and pXG6C1 contains an alpha-globin sequence.

J Biol Chem, 1980 Jun 25, 255(12), 5643 - 8
Energy-transducing H+-ATPase of Escherichia coli . Reconstitution of proton translocation activity of the intrinsic membrane sector; Negrin RS et al.; The intrinsic membrane sector (Fo) of the H+-ATPase complex of Escherichia coli has been purified, incorporated into liposomes, and its proton-translocating activity reconstituted . The Fo sector was prepared by treating a purified, particulate, F1FO-ATPase preparation with EDTA to solubilize the F1-ATPase . The resulting particulate Fo fraction was incorporated into liposomes of E . coli phospholipids by sonication . Proton efflux from these liposomes was measured with a pH electrode after imposition of a membrane potential . The kinetics of proton efflux fits that predicted by the Goldman-flux equation . The rate of proton efflux was increased maximally more than 100-fold on incorporation of the Fo sector into the liposomes . The rate of H+ efflux varied directly with the amount of Fo material added during reconstitution . Dicyclohexylcarbodiimide blocked Fo-mediated H+ efflux . Inhibition was shown to be due to reaction of dicyclohexylcarbodiimide with a specific proteolipid subunit of Fo . The preparation of Fo used in these studies contained the three proteins that had previously been identified as likely subunits of Fo (Foster, D . L., and Fillingame, R . H . (1979) J . Biol . Chem . 254, 8230-8236) . It remains to be determined whether all three components are required for reconstitution of proton translocation activity.

Nucleic Acids Res, 1980 Jun 25, 8(12), 2709 - 23
Alterations in two conserved regions of promoter sequence lead to altered rates of polymerase binding and levels of gene expression; Stefano JE et al.; Characterization of recombinant lac promoters highlights the importance of two regions of sequence conservation in promoters . The "Pribnow box" sequences are necessary for specific transcription in this system . This specificity is maintained when a mutated upstream sequence is introduced . However, changing the upstream DNA sequences influences both the rate of RNA polymerase binding in vitro and levels of expression in vivo.

Nucleic Acids Res, 1980 Jun 25, 8(12), 2561 - 75
Complete nucleotide sequence of the haemagglutinin gene from a human influenza virus of the Hong Kong subtype; Both GW et al.; The complete nucleotide sequence has been determined for a cloned double-stranded DNA copy of the haemagglutinin gene from the human influenza strain A/NT/60/68/29C, a laboratory-isolated variant of A/NT/60/68, an early strain of the Hong Kong subtype . The gene is 1765 nucleotides long and contains information sufficient to code for a protein of 566 amino acids, which includes a hydrophobic leader peptide (16 residues), HA1 (328), HA2 (221) and an arginine residue which joins the HA subunits . Comparison of the predicted amino acid sequence for 29C haemagglutinin with protein sequence data available for HA from other influenza strains shows that no potential coding information is lost by processing of the mRNA . A comparison of the amino acid sequences predicted from the gene sequences for 29C and fowl plague virus haemagglutinins, (1) indicates the extent to which changes can occur in the primary sequence of different regions of the protein, while maintaining essential structure and function.

J Biol Chem, 1980 Jun 25, 255(12), 5511 - 3
Fluoride, pyrophosphate, and base release from 2'-deoxy-2'-fluoronucleoside 5'-diphosphates by ribonucleoside-diphosphate reductase; Stubbe JA et al.; Ribonucleoside-diphsophate reductase from Escherichia coli catalyzes release of fluoride, inorganic pyrophosphate, and base from 2'-deoxy-2'-fluoronucleoside diphosphates . This reaction is accompanied by inactivation of the enzyme and an increase in absorbance at 314 nm of the inactivated protein . 2'-Deoxy-2'-fluoroadenosine 5'-diphosphate requires two turnovers per inactivation, whereas 2'-deoxy-2'-fluorocytidine 5'-diphosphate requires 100 turnovers per inactivation.

Biochemistry, 1980 Jun 24, 19(13), 3001 - 4
Electrophoresis of duplex deoxyribonucleic acid in multiple-concentration agarose gels: fractionation of molecules with molecular weights between 2 X 10(6) and 110 X 10(6); Serwer P; By use of multiple-concentration agarose gels, the distance migrated by linear, duplex DNA during agarose gel electrophoresis has been measured as a function of agarose concentration (A) and molecular weight of the DNA (Mr) for molecules with an Mr between 1.88 X 10(6) and 110 X 10(6) . Conditions for obtaining a linear plot of log Mr as a function of distance migrated (D) have been found for DNA molecules with an Mr between 5.47 X 10(6) and 110 X 10(6); improved conditions for fractionating such molecules are described . The ratio of the D of a DNA with an Mr of 26.5 X 10(6) to the D of a DNA with an Mr of 77 X 10(6) was plotted as a function of A and electrical field (E) . By use of A values between 0.075 and 0.70% and a constant E, this plot had a single maximum . The maximal value of the above ratio was a decreasing function of E, and the A at this maximal value was also a decreasing function of E.

Biochemistry, 1980 Jun 24, 19(13), 2901 - 7
Phosphorylated intermediate of alkaline phosphatase; Cocivera M et al.; We have measured the phosphorylation of the subunits of alkaline phosphatase in the steady state with several substrates and at several pH values . Our results vary from 80% phosphorylation of both subunits at pH7 to only 9% at pH 10 . There is no evidence of anticooperativity . With the measurement of kcat, we are able to evaluate rate constants in a minimal scheme . The results show that the main rate influencing steps ar chemical dephosphorylation and dissociation of phosphate . The predominates at pH 7.0 but declines in importance as the pH is raised . Our rate constants for dissociation of phosphate are in agreement with recent NMR studies.

Biochemistry, 1980 Jun 24, 19(13), 2882 - 8
Purification and properties of the inducible enzyme cyanase; Anderson PM; Cyanase (cyanate hydrolase EC 3.5.5.3) has been purified 270-fold to a high state of purity from Escherichia coli B . The native enzyme has a molecular weight of approximately 150 000 as estimated by sucrose density gradient centrifugation and gel-filtration chromatography on Bio-Gel P-300 . The enzyme is an oligomer composed of apparently identical subunits which have a molecular weight of approximately 15 000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Amino acid analyses showed that the enzyme contains no tryptophan and a single histidine residue, based on a subunit molecular weight of 14 661 . Catalytic hydrolysis of cyanate was found to be dependent on the patience of bicarbonate and to be affected by ionic strength . The concentration of bicarbonate required to give half-maximal activity in the presence of 2 mM potassium cyanate was 0.1 mM . The apparent Km for cyanate in the presence of 3 mM bicarbonate is 0.6 mM . The initial product of the reaction is carbamate (or a related, unstable compound and/or carbamate precursor) which subsequently decomposes to ammonia and bicarbonate.

Biochemistry, 1980 Jun 24, 19(13), 2965 - 76
Modulation of transcription from chromatin assembled in vitro; Holland LJ et al.; A small plasmid DNA was assembled into chromatin in vitro by incubation in an extract prepared frog eggs of Xenopus laevis . The plasmid DNA contrained the regulatory region of the Escherichia coli lac operon, the transcription of which is under positive regulation by catabolite activator protein (CAP) and negative regulation by lac repressor . After incubation in the egg extract the plasmid DNA acquired approximately 60% of the predicted maximum number of nucleosomes . Chromatin was treated with protein and DNA cross-linking agents prior to transcriptin in order to demonstrate that regions of the DNA organized into nucleosomes served as templates for transcription . Cross-linking abolished transcription of chromatin but had no effect on transcription of the DNA, suggesting that transcription of untreated chromatin was not solely attributable to nucleosome-free regions . In support of this conclusion, the average size of the RNA transcribed from chromatin was approximately 1000 bases, which was approximately 5 times longer than the average distance between nucleosomes . Transcription of in vitro assembled plasmid chromatin by E . coli RNA polymerase was stimulated by catabolite activator protein . The CAP-mediated stimulation of transcription was detectable as an increase in total transcription that was specific to chromatin made from a plasmid containing the lac regulatory DNA sequences . The specific increase in the amount of RNA whose synthesis was initiated within the lac region was demonstrated by hybridization of transcription products to complementary DNA fragments bound to nitrocellulose filters . Preliminary investigation of the action of lac repressor suggested that it also modulated transcription from the chromatin template.

Biochem J, 1980 Jun 15, 188(3), 715 - 23
The nature of the link between potassium transport and phosphate transport in Escherichia coli; Russell LM et al.; A series of mutants of Escherichia coli, combining defects in either of the two phosphate transport systems with defects in one or more of the potassium transport systems, was used to study the nature of the previously observed obligatory requirement for each one of these ions in the transport of the other . The results show that no pair of systems is obligatorily linked, and that either ion can be transported by any one of its systems, provided that a means of entry for the other ion is available . Furthermore, in the total absence of Pi, K+ entry accompanies the transport of other anions, such as aspartate, glutamate, sn-glycero-3-phosphate and glucose 6-phosphate . The results indicate that Pi and the other anions enter by symport with protons, and that a simultaneous K+/H+ exchange, which would serve to maintain the intracellular pH, is responsible for the observed K+ 'symport' with these anions.

Biochim Biophys Acta, 1980 Jun 13, 613(2), 309 - 17
Separation and characterization of NAD- and NADP-specific succinate-semialdehyde dehydrogenase from Escherichia coli K-12 3300; Cozzani I et al.; Two distinct proteins endowed with succinate-semialdehyde dehydrogenase (succinate-semialdehyde:NAD(P)+oxidoreductase, EC 1.2.1.16) activity were separated and partially purified by ammonium sulphate fractionation or Sephadex G-200 gel-filtration or both . They differ by coenzyme specificity (NAD or NADP), molecular weight, temperature and pH resistance, pH-activity curves, beta-mercaptoethanol activation . Moreover, the NADP-specific enzyme catalyzes only the oxidation of succinate-semialdehyde among a number of aldehydes tested, whereas the NAD-specific form is active also towards n-butyraldehyde . The Km for the substrate is also appreciably different according to the coenzyme specificity, while the Km values for NAD and NADP are quite similar . Finally, the growth of the cells on gamma-aminobutyrate as the sole source of nitrogen resulted in enhanced level of the NAD-dependent succinate-semialdehyde dehydrogenase, with concurrent decrease of the alternate enzyme activity . On the basis of the above results, distinct metabolic roles are suggested for the two enzymes forms.

Biochim Biophys Acta, 1980 Jun 13, 613(2), 439 - 47
Identification of ribonuclease P activity from chick embryos; Bowman EJ et al.; RNAase P (EC 3.1.26.5) activity has been identified in chick embryo thigh tissue on the basis of specific cleavage of Escherichia coli 129 nucleotide tRNATyr precursor and has been partially purified by the procedure used for human tissue culture KB cell RNAase P . RNAase P from chick resembles the KB cell RNAase P in substrate specificity, requirement for a divalent cation (Mg2+) and a monovalent cation (K+, Na+ or NH4+) for activity, inhibition by bulk tRNA, ready inactivation by proteases, and increasing instability; with purification . RNAase P activity is also present in whole chick embryos, as well as in liver and heart tissues . Furthermore, crude preparations of RNAase P from chick embryo heart tissue are relatively free of contaminating nucleases.

Nature, 1980 Jun 12, 285(5765), 456 - 63
Expression of cloned beta-endorphin gene sequences by Escherichia coli; Shine J et al.; DNA coding for the opiate peptide beta-endorphin has been cloned into bacterial plasmids in such a way as to direct the synthesis of a hybrid beta-galactosidase/beta-endorphin protein . This hybrid protein can readily be cleaved in vitro to release biologically active beta-endorphin.

Nucleic Acids Res, 1980 Jun 11, 8(11), 2489 - 98
Characterization of Mg2+-induced conformational change in the 50S ribosomal subunit by differential hydrogen exchange; Bonnet D et al.; The technique of differential hydrogen exchange allows detection of a conformational change in the 50S subunit of Escherichia coli ribosome when the magnesium concentration is lowered in a range where ribosomal activity is fully preserved . This change is characterized by a seventy-fold acceleration of about thirty labile hydrogens in the case of a Mg2+ jump from 10 mM to 2 mM . The small number of hydrogens involved can explain the difficulty in detecting this change by other methods.

Nucleic Acids Res, 1980 Jun 11, 8(11), 2453 - 60
Selective blotting of restriction DNA fragments on nitrocellulose membranes at low salt concentrations; Nagamine Y et al.; The pattern of restriction DNA fragments transferred from agarose gel to nitrocellulose membranes (Southern's technique) can be affected by the salt concentration of the transfer solvent.

Nucleic Acids Res, 1980 Jun 11, 8(11), 2547 - 59
Binding of non-substrate nucleotides to a restriction endonuclease: a model for the interaction of bam HI with its recognition sequence; Hinsch B et al.; The kinetic constants of the site-specific endonuclease Bam HI for various substrates were determined and binding of non-substrate nucleotides to the enzyme was studied . Agarose gel assays in combination with an integrated Michaelis-Menten equation were used for the evaluation of data . The turnover number was 2.2 min-1 at 37 degrees C with pJC80 DNA as the substrate . It depends on the conformation and base composition of the substrate . Michaelis constants also depend on substrate conformation . Non-substrate polynucleotides were found to inhibit Bam competitively with KI ranging from 10(-6) to > 10(-3) M depending on base composition, base pairing, and helix conformation . Dinucleotides showed sequence-specific, competitive inhibition with KIs ranging from 10(-5) to > 10(-3) M . Mononucleotides and -nucleosides acted noncompetitively . Binding was influenced by the extent of phosphorylation, but not by the nature of the base . KIs varied between 10(-3) and 10(-2) M . The results are discussed with respect to the recognition requirements of Bam HI.

Nucleic Acids Res, 1980 Jun 11, 8(11), 2499 - 515
Interaction of polynucleotides with natural and model membranes; Budker VG et al.; Polynucleotides adsorb on natural and model phospholipid membranes in the presence of Mg2+-cations . Adsorption of nucleic acids on membranes results in a considerable change of their secondary structure . The presence of model phosphatidylcholine membranes greatly stimulates the rate of the synthesis of RNA by E . coli RNA-polymerase on DNA template.

Nucleic Acids Res, 1980 Jun 11, 8(11), 2397 - 411
Localisation of a series of intra-RNA cross-links in 16S RNA, induced by ultraviolet irradiation of Escherichia coli 30S ribosomal subunits; Zwieb C et al.; Mild ultraviolet irradiation of E . coli ribosomal subunits leads to the formation of a number of intra-RNA cross-links, in addition to the RNA-protein cross-links already reported (see refs . 9, 10) . After partial ribonuclease digestion of the RNA from irradiated subunits, complexes containing these intra-RNA cross-links can be isolated on a two-dimensional gel electrophoresis system, and subjected to sequence analysis . A series of these cross-linked complexes is described, and the cross-linked RNA regions are compared with the secondary structures derived for 16S RNA (see refs . 6, 7).

Nucleic Acids Res, 1980 Jun 11, 8(11), 2377 - 95
An experimentally-derived model for the secondary structure of the 16S ribosomal RNA from Escherichia coli; Glotz C et al.; Ribonucleoprotein fragments are isolated by mild ribonuclease digestion of E . coli 30S ribosomal subunits, and are deproteinized and subjected to a second partial digestion . Base-pairing between the resulting small RNA fragments is investigated using the two-dimensional gel electrophoresis procedure already reported (see Ref . 1) . The interactions thus found are incorporated into a secondary structure model covering approximately 80% of the 16S RNA.

J Biol Chem, 1980 Jun 10, 255(11), 4973 - 5
Base-pairing in conserved 3' end of 18 S rRNA as determined by psoralen photoreaction and RNase sensitivity; Darzynkiewicz E et al.; Wheat and rabbit 18 rRNAs radiolabeled at the 3' end with {5'-32P}pCp were analyzed by polyacrylamide gel electrophoresis after chemical cleavage or partial enzymatic digestion under nondenaturing conditions . rRNA was similarly analyzed after photoreaction with 4'-aminomethyl-4,5',8-trimethylpsoralen and photoreversal of the resulting pyrimidine cross-links . The digestion patterns indicated the presence of a base-paired structure within a conserved 3'-terminal sequence . This structure corresponds to the 3'-proximal hairpin configuration suggested previously for the small subunit rRNAs of Escherichia coli, yeast, rat, and silkworm on the basis of their nucleotide sequences.

Biochemistry, 1980 Jun 10, 19(12), 2696 - 702
Turbidity measurements in an analytical ultracentrifuge . Determinations of mass per length for filamentous viruses fd, Xf, and Pf3; Berkowitz SA et al.; An analytical ultracentrifuge has been used to measure light-scattering intensities by the transmittance method . The technique, which is applicable to particles of many sizes and shapes, has the principal advantage that samples can be kept free of dust during the measurements . Also, sample volumes are small, and the scanner and interference optics can be used simultaneously to obtain, for a given sedimenting boundary, turbidity steps at different wavelengths and the concentration step . In the present application the data yield mass per length estimates for three filamentous viruses, 19 100 daltons/nm for fd, 19 600 daltons/nm for Pf3, and 19 100 daltons/nm for Xf.

J Biol Chem, 1980 Jun 10, 255(11), 5300 - 5
Q beta replicase containing wild type and mutant tufA and tufB gene; Blumenthal T et al.; The protein synthesis elongation factor EF-Tu, complexed with EF-Ts, forms part of Q beta RNA replicase . In an effort to determine its function in the RNA synthesis reaction, we have developed procedures which allow us to replace the endogenous EF-Tu in purified Q beta replicase with EF-Tu from a variety of sources . In this communication we report purification of EF-Tu from strains containing (a) a wild type tufA gene only, (b) a kirromycin-resistant mutant tufA gene only, and (c) a kirromycin-resistant mutant tufA gene and a mutant tufB gene which codes for EF-Tu that does not bind ribosomes . When each of these EF-Tu preparations is inserted in Q beta replicase, the wild type tufA gene product and and the tufB gene product function appearently normally, but the kirromycin-resistant tufA gene product causes the formation of an altered enzyme . The Q beta replicase containing kirromycin-resistant EF-Tu is unstable; it is rapidly inactivated in the reaction mixture, even at temperatures as low as 20 degrees C . This property results in an apparent increase in template specificity; while wild type Q beta replicase will transcribe poly(C) and other synthetic RNA species, the mutant enzyme will do so only in the presence of Mn2+, which reduces template specificity . The kirromycin-resistant Q beta replicase will also transcribe Q beta RNA . The results imply that EF-Tu is involved in maintenance of enzyme structure, which, in turn, is implicated in template specificity.

J Biol Chem, 1980 Jun 10, 255(11), 5154 - 8
The role of tryptophan in aspartate transcarbamylase; Foote J et al.; Replacement of 7-azatryptophan for tryptophan in two positions on the catalytic chain of aspartate transcarbamylase results in changes in the enzyme's homotropic and heterotropic interactions although there is no change in the enzyme's specific activity . The extent of azatryptophan incorporation was quantitated by amino acid analysis which showed that 85% of the tryptophan residues had been replaced . The substituted enzyme is activated by ATP and inhibited by CTP to a greater extent than is the native enzyme . The aspartate saturation curve in the presence of ATP is identical for the two enzymes, but the curve in the presence of CTP and without effectors is shifted toward higher aspartate concentrations for the azatryptophan-substituted enzyme . At low aspartate concentrations, the native enzyme is activated to a greater extent by the substrate analog succinate . These data suggest that the substitution renders the low substrate affinity conformational state of the enzyme less catalytically efficient . This interpretation is in agreement with possible side chain interactions observed in the three-dimensional structure of the enzyme.

J Biol Chem, 1980 Jun 10, 255(11), 5075 - 81
Different sidedness of functionally homologous essential thiols in two membrane-bound phosphotransferase enzymes of Escherichia coli detected by permeant and nonpermeant thiol reagents; Haguenauer-Tsapis R et al.; The membrane-bound Enzyme IIbgl and IIglc are both inactivated in vivo by the sulfhydryl reagent N-ethylmaleimide . The former is also inhibited by the hydrophilic sulfhydryl reagents p-chloromercuribenzoic acid and p-mercuriphenylsulfonic acid, while the latter is resistant to these reagents . However, inhibition of this enzyme is observed after impairment, either transient or permanent, of the permeability barrier of bacterial envelopes . Since p-chloromercuribenzoic acid and p-chloromercuriphenylsulfonic acid are able to cross the outer membrane of Escherichia coli, their failure to inhibit in vivo Enzyme IIglc must be due to their inability to cross the inner membrane of the bacteria . It would therefore appear that sensitive thiol group(s) of Enzyme IIglc and Enzyme IIbgl, in spite of their functional similarity, exhibit opposite orientation within the cytoplasmic membrane, the first enzyme having an -SH group accessible from the outer surface of the membrane, while the second has an -SH group accessible from the inner surface of the membrane . The present results strengthen the view that these two enzymes have in asymmetric orientation within the membrane as already suggested by their vectorial function.

J Biol Chem, 1980 Jun 10, 255(11), 5208 - 14
A DNA-dependent ATPase from T4-infected Escherichia coli . Purification and properties of a 63,000-dalton enzyme and its conversion to a 22,000-dalton form; Panuska JR et al.; A DNA-dependent ATPase with a molecular weight of 63,000 has been purified to near homogeneity from T4-infected Escherichia coli . This enzyme is not present in uninfected E . coli . It is present in E . coli infected with amber mutants of gene 44 or gene 62 and with the data mutant . The enzyme can be eluted from single-stranded DNA-cellulose at NaCl molarities greater than 0.6 M and from ATP agarose with 80 mM MgATP . The enzyme hydrolyzes MgATP or MgdATP to the diphosphates with equal maximum velocities and the Km values are 0.30 and 0.75 mM, respectively . The enzyme hydrolyzes MgCTP with 13% and MgUTP with 7% of the velocity observed with MgATP . Apparent Km values are reported for single-stranded T4 DNA and for a series of synthetic polynucleotides . The 63,000-dalton enzyme can be cleaved proteolytically to an active 22,000-dalton form . This can be demonstrated by storage of infected cells, by mixing of cell extracts, and by inhibition with phenylmethylsulfonyl fluoride . The Mr = 22,000 enzyme cross-reacts with antibody made to the Mr = 63,000 enzyme . This antibody inhibits the 22,000-dalton species . The 22,000-dalton enzyme forms a complex with gene 32 protein in the absence of DNA.

C R Seances Acad Sci D, 1980 Jun 9, 290(21), 1365 - 8
{Sulfonamide-dependent growth of a strain of Escherichia coli K12 Thy- on Mueller-Hinton medium}; Frelat G et al.; The Mueller Hinton medium does not allow the growth of Escherichia coli Thy- strains . This effect is due to the presence of uridine (or a derived compound) which interferes with the function of thymidine phosphorylase . The presence of sulphonamides, in some E . coli K12 Thy- mutants, overcomes this inhibition . The same phenomenon of rescue by sulphonamides has been reproduced in a minimal medium containing thymine and uridine . The biochemical and clinical implications of this observation are discussed.

Biochim Biophys Acta, 1980 Jun 6, 598(3), 641 - 6
Correlation between temperature range of growth and structural transitions in membranes and lipids of Escherichia coli K12; Janoff AS et al.; Purified cytoplasmic and outer membranes isolated from cells of wild-type Escherichia coli grown at different temperatures were labelled with 1,6-diphenyl-1,3,5-hexatriene and analyzed using fluorescence polarization techniques . Lipids extracted from the membranes were similarly analyzed using fluorescence polarization . The thermotropic structural transition in outer membranes changed as a function of growth temperature . The structural transition in cytoplasmic membranes and lipids extracted from either cytoplasmic or outer membranes did not change with growth temperature . These data suggest that adaptive changes which occur in the outer membrane determine the temperature range of growth of E . coli . These changes apparently require alterations in outer membrane components other than phospholipids.

Nature, 1980 Jun 5, 285(5764), 407 - 9
5-Methoxypsoralen, an ingredient in several suntan preparations, has lethal, mutagenic and clastogenic properties; Ashwood-Smith MJ et al.; Many furocoumarins found in several species of plant are potent photosensitizing agents known to cause lethal and mutagenic effects in a wide range of organisms, from viruses to man . Their role in the aetiology of cancer is debatable, but work has focused on the PUVA (psoralen-UVA) treatment of psoriasis with 8-methoxypsoralen (8-MOP) and near UV radiation . Bergaptene (5-methoxypsoralen, 5-MOP) is a major constiutent of oil of bergamot, and might be expected to have qualitatively similar photosensitizing properties to 8-MOP . Although 5-MOP is widely used as a stimulus to melanin deposition in several suntan preparations surprisingly little is known about its basic photobiology . We report here that 5-MOP has the expected properties of other biologically active furocoumarins . These properties include lethal and mutagenic photosensitization of bacteria, 'dark' induced frameshift mutagenesis in bacteria, and lethal and clastogenic effects on mammalian cells in tissue culture.

Clin Pediatr (Phila), 1980 Jun, 19(6), 401 - 4
Neonatal hypothermia in a developing country; El-Radhi AS et al.; Fifty newborn Iraqi children with hypothermia were studied to determine causes and incidence of the precipitating factors . The majority of infants more than three days old (late-onset) had evidence of infection, particularly septicemia . The overall mortality rate was 26 per cent--(42 per cent in low birth weight infants (LBW) . Early-onset hypothermia in the first three days of life is due to exposure to cold without evidence of infection and has a good prognosis . The most common finding in our series was a high incidence of aspiration pneumonia in late-onset hypothermia . Antibiotics effective against Escherichia coli, such as gentamicin, should be given from the outset to all patients with late-onset hypothermia without waiting for laboratory proof of infection.

Carcinogenesis, 1980 Jun, 1(6), 459 - 68
Structural identification of the pyrimidine derivatives formed from N-(deoxyguanosin-8-yl)-2-aminofluorene in aqueous solution at alkaline pH; Kriek E et al.; The major aminofluorene-DNA derivative formed from the carcinogen N-acetyl-2-aminofluorene in vivo in rat liver is N-(deoxyguanosin-8-yl)-2-aminofluorene . This nucleoside is hydrolyzed in aqueous solution at alkaline pH through the 7-8 guanine bond to form two pyrimidine derivatives which were separated by Sephadex LH-20 column chromatography and thin-layer chromatography on silica . From chemical, u.v., i.r., n.m.r . and mass spectral analysis the pyrimidine derivatives have been identified as 1-{6-(2,5-diamino-4-oxopyrimidinyl-N6-deoxyriboside)}-3-(2-fluorenyl)ureas, which probably are stereoisomers . Similar products were isolated from enzymatic hydrolysates of DNA reacted with N-hydroxy-2-aminofluorene under mildly acidic conditions (pH 5) and subsequent treatment with 0.1 N NaOH . Kinetic studies of the hydrolysis reaction showed that it occurs already at a measurable rate at pH 9.5 and 37 degrees C . The reaction is catalyzed by Mg2+ and Mn2+ ions and by alkaline phosphatase from E . coli.

J Helminthol, 1980 Jun, 54(2), 135 - 46
Development of Pelodera strongyloides (Schneider, 1860) Schneider, 1866 (Nematoda: Rhabditidae) in culture; Cliff GM et al.; Dauerlarvae of Pelodera strongyloides, recovered from two species of lemmings, Dicrostonyx groenlandicus (Traill) and Lemmus trimucronatus (Richardson) trapped at Eskimo Point, N.W.T, were cultured on agar medium with E . coli . Development from egg to adult stage was followed . Eggs hatched between 22 and 26 hours at 22 degrees C . The first moult occurred 24 to 28 hours after the eggs hatched, the second at 40 to 48 hours, the third at 60 to 64 hours and the fourth at 84 to 88 hours at 22 degrees C . Adults lived approximately 5 to 6 days and females oviposited for 2 to 3 days during this time . All stages were measured and described . The effect of temperature on development was examined . Dauerlarvae survived freezing temperatures, short periods of desiccation and prolonged periods without food.

Biken J, 1980 Jun, 23(2), 69 - 75
Forward mutation assay for screening carcinogens by alkaline phosphatase constitutive mutations in Escherichia coli K-12; Izutani K et al.; A new forward mutation assay was developed with Escherichia coli using alkaline phosphatase (APase) constitutive mutations as a genetic marker . Mutation in any one of the three regulator genes (phoR, T and S) is known to make the cell constitutive for APase synthesis and enable the mutants to form larger colonies on beta-glycerophosphate plate under the condition of excess inorganic phosphate . This property was used for qualitative and quantitative assay of chemical mutagens . Attempts were made to construct suitable strains for this assay by introduction of various genetic traits that might increase the sensitivity of mutation . Three known chemical mutagens (N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), methyl methanesulfonate (MMS), and 4-nitroquinoline-1-oxide (NQNO)) were employed as reference compounds in the quantitative assay . Among the strains constructed, a tester strain with genetic markers tif-1, uvrA and pKM101 was the most sensitive to these compounds, judging from tests on concentration-dependent mutagenic activity . The merits and limitations of the present system are discussed.

J Math Biol, 1980 Jun, 9(4), 389 - 98
Analysis of a cell cycle model for Escherichia coli; Alberghina L et al.; Ribosome and protein synthesis, DNA replication and cell division in Escherichia coli cells are described by a mathematical model that integrates previous descriptions in quantitative terms and proposes a new formalization to relate ribosome net synthesis to cell growth . The model assumes a cell size control of DNA replication and therefore is structurally divided into two subsystems: the first, whose state variables are ribosomes and protein, and the second, which is activated when the protein level reaches a threshold and which is comprised of DNA replication and cell division . The dynamics of the entire system is set only by the first subsystem: the values of its parameters determine whether the cells will be in a resting condition or will grow exponentially and in the latter case the resulting duplication time, while the structure and the parameter values of the second subsystem determine the size and the composition of the cell and the timing of DNA replication during the cycle . Relationships are derived that allow a simple determination of the time of initiation and of termination of DNA replication and the number of chromosome origins involved in any possible cell cycle as well as the macromolecular levels at the beginning of a cycle and on the average in a population of cells in balanced exponential growth.

J Gen Microbiol, 1980 Jun, 118(2), 515 - 21
Genetic and molecular characterization of R plasmids incompatible with R387 (IncK); Tschape H et al.; More than 70 conjugative R plasmids have been isolated from wild-type strains originating mainly in South-East Europe and identified as incompatible with the reference plasmid R387 of the incompatibility group K . These plasmids, governing different resistance patterns, have been characterized as P1 cotransducible species of between 50 and 60 mega-daltons . In contrast to the genetic similarity between all these plasmids and the reference type R387, their DNA revealed different digestion patterns after EcoRI treatment, although a number of common fragments could be identified . The molecular and genetic properties of these plasmid species demonstrate a phylogenetic relatedness.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3259 - 63
Four sizes of transcript produced by a single sea urchin gene expressed in early embryos; Lee AS et al.; This report concerns a set of sea urchin egg and embryo transcripts complementary to a single-copy region of a cloned DNA fragment (Sp88) . Three distinct 16-cell embryo polysomal RNA species were found to hybridize with this fragment . These RNAs are about 1700, 3000, and 4000 nucleotides (nt) in length, and the same species were identified in unfertilized eggs . A significant fraction of all three species of the egg and early embryo transcripts is polyadenylylated . At gastrula stage Sp88 transcripts are almost completely confined to the nucleus {Lev, Z., Thomas, T . L., Lee, A . S., Angerer, R . C., Britten, R . J . & Davidson, E . H . (1980) Dev . Biol, 75, in press} . The Sp88 transcripts of gastrulae are present as a fourth RNA species approximately 5800 nt in length . The four species share a sequence element of cloned DNA fragment that is about 1000 nt long . These RNAs constitute a set of alternative partially overlapping transcripts from the same genomic region.

Med Hypotheses, 1980 Jun, 6(6), 611 - 25
Theoretical mechanisms for synthesis of carcinogen-induced embryonic proteins . VI . Radiation; Hancock RL; The following is an attempt to devise a theory of specific induction processes required of the neoplastic transformation using the non-specific carcinogenic agent - radiation . A variety of biological considerations including comparative radiosensitivity, radiation effects on chromatin and enzymes, radiomimetic chemical induction of chromosomal anomalies, lethality and the tRNA function are also presented . These topics serve as background for elaborating a scheme of how a specific array of genes could become decontrolled . A concept derived involves the fixation of despiralized genic areas which are induced by hypomethylated DNA caused by anomalous DNA methylation . This process could be a potentially critical part of the irradiation-induced carcinogenic event . The concept of fixation of chromatin in an informational sense leads to a mechanism requiring a classic mutation, modified by a repair process that ultimately leads to an epigenetic event . More specifically it would appear that a critical target to induce the neoplastic response from a cell with irradiation could be the DNA responsible for the template sites (or at least a secondary area that indirectly could cause inactivation of this site) of the genes for DNA methylation . This would not necessarily be the only genic change required but one can derive gene derepressions from this type of molecular lesion . A similar scheme for gene repression has not been devised in this writing beyond the simplistic, although not unwarranted, viewpoint of direct DNA damage.

Gene, 1980 Jun, 10(1), 63 - 7
Plasmid screening at high colony density; Hanahan D et al.; A procedure is described for screening bacterial colonies containing recombinant plasmids by nucleic acid hybridization at high density, i.e., at 100 000 colonies per 150 mm diameter plate . Small colonies are established on nitrocellulose filters from which they can be faithfully replicated to additional filters . Chloramphenicol amplification may be carried out in situ before screening . The filters may be kept frozen for long-term storage of colonies which may be further replicated after thawing.

Infect Immun, 1980 Jun, 28(3), 818 - 23
Mitogenicity of a lipid-deficient lipoprotein from a mutant Escherichia coli strain; Bessler WG et al.; From the mutant bacterial strain Escherichia coli JE5511 lpp lpm, muropeptide-containing and muropeptide-free lipoproteins were prepared . By gas chromatography and by infrared spectroscopy we showed that the products were deficient in the two ester-bound N-terminal fatty acids, but still carried the amide-linked fatty acid . Mutant lipoproteins were tested for mitogenicity in lipopolysaccharide nonresponder C3H/HeJ mice by incorporation of {3H}thymidine and {3H}uridine and by hemolytic plaque assays for immunoglobulin-secreting plasma cells . Our results showed that the mutant lipoproteins still exhibited marked mitogenicity toward mouse B-lymphocytes, although the activity of the products was reduced in comparison to the wild-type lipoprotein . Thus, the presence of one fatty acid in the N-terminal part of lipoprotein is sufficient to bring about mitogenicity.

Infect Immun, 1980 Jun, 28(3), 1051 - 3
Physiochemical properties of a heat-stable enterotoxin produced by Escherichia coli of human origin; Madsen GL et al.; Concentrated cell-free filtrates, prepared from a human strain of enterotoxigenic Escherichia coli, were subjected to isoelectric focusing, molecular sieve chromatography, and polyacrylamide disc gel electrophoresis . Isoelectric focusing in a pH 3 to 5 gradient resulted in two biologically active peaks, I and II, that electrofocused at pI 1.5 and 3.8, respectively . Molecular sieve chromatography of the major enterotoxic peak (II) at pH 3.8 indicated a molecular weight of 2,500 . Polyacrylamide disc gel electrophoresis of ST revealed a single protein band containing enterotoxic activity.

Infect Immun, 1980 Jun, 28(3), 1038 - 40
Heat-stable enterotoxins from Escherichia coli P16; Burgess MN et al.; Escherichia coli P16 infant mouse active heat-stable enterotoxin may be fractionated into two distinct active moieties by ion-exchange chromatography, Sephadex G-25 chromatography, and isoelectric focusing.

Eur J Biochem, 1980 Jun, 107(2), 403 - 7
Transfer RNA labeling of Escherichia coli methionyl-tRNA transformylase; Hountondji C et al.; Homogeneous methionyl-tRNA transformylase from Escherichia coli can react with periodate-treated tRNAMetf to form a Schiff's base through a free amino group (probably the epsilon-amino group of a lysine) and the 2',3'-aldehyde groups created at the 3'-terminal ribose of tRNA . This reaction is reflected by the loss of activity of the enzyme at saturating tRNA dialdehyde and upon reduction of the Schiff's base by NaBH4 . the kinetics of inactivation (37 degrees C, pH 8.5) level off at 50% of the initial enzymic activity . In the presence of 2 mM cyanohydridoborate, a mild reducing agent which leaves intact the reacting aldehyde groups of oxidized tRNA but continuously reduces the Schiff's base in equilibrium, the activity of the enzyme can be destroyed by 100%, at a rate of 0.044 min-1, with the parallel covalent incorporation of close to one tRNA molecule per enzyme molecule . Selectivity of the labeling is also supported by the demonstration that, prior to Schiff's base formation, modified tRNA binds the transformylase with equilibrium constant and stoichiometry in good agreement with those for the active binding of unmodified tRNa . Moreover intact tRNA competes for the inactivation by the dialdehyde derivative with an affinity constant identical to that for its active binding to the enzyme

Eur J Biochem, 1980 Jun, 107(2), 375 - 9
Novel intermediates in the synthesis of maltose-binding protein in Escherichia coli; Randall LL et al.; Nascent intermediates in the synthesis of maltose-binding protein, a periplasmic protein in Escherichia coli, were demonstrated both in vivo and in vitro . They are likely to result from a drastic reduction in the rate of elongation at specific sites on the mRNA leading to detectable accumulation of distinct species of incomplete polypeptides . In order to reach its final destination in the periplasmic space, maltose-binding protein is transferred across the cytoplasmic membrane as it is elongated . It is possible that variations in the rate of elongation are involved in this export process.

Orig Life, 1980 Jun, 10(2), 137 - 59
Limits to life at low temperatures and at reduced water contents and water activities; Mazur P; Liquid water is generally considered an absolute requisite for functional life; consequently, life is expected to function only over the range of temperatures that permit its existence . These limits, however, do not apply to cell survival . Some cells can survive the closest attainable approach to 0 K, and some can survive the loss of over 99% of their water.

J Bacteriol, 1980 Jun, 142(3), 1049 - 54
Regulation of ribonucleic acid polymerase synthesis during restriction of an Escherichia coli mutant temperature sensitive for transcription factor sigma; Blumenthal RM et al.; An Escherichia coli mutant temperature sensitive for the sigma subunit of ribonucleic acid polymerase was shifted to restrictive temperatures . In response to these restrictions the transcription of rpoBC increased markedly, and the synthesis rates of the beta and beta' subunits of ribonucleic acid polymerase increased . The ratio of the beta and beta' synthesis rates (beta/beta') decreased.

J Bacteriol, 1980 Jun, 142(3), 1040 - 4
Alcohol-induced changes in the phospholipid molecular species of Escherichia coli; Berger B et al.; In Escherichia coli, the additon of ethanol resulted in the synthesis of an increased proportion of phospholipids containing two unsaturated fatty acids . The addition of hexanol resulted in the opposite effect, an increase in the proportion of monounsaturated molecular species . The alcohol-induced changes were quantitatively similar to those caused by changing growth temperature . These results suggest that both adaptation to temperature and alcohol-induced changes in lipid composition share some common regulatory features.

J Bacteriol, 1980 Jun, 142(3), 1025 - 8
Biotin regulatory (bir) mutations of Escherichia coli; Campbell A et al.; Most mutants selected for derepression of the biotin operon required elevated concentrations of biotin for growth . Mutant extracts were deficient in holoenzyme synthetase activity.

J Bacteriol, 1980 Jun, 142(3), 1004 - 6
Conditional-lethal deoxyribonucleic acid polymerase I mutant of Escherichia coli; Shizuya H et al.; A new deoxyribonucleic acid polymerase I mutant of Escherichia coli was isolated among conditional lethal mutants . Deoxyribonucleic acid replication in the mutant ceased in 20 min after the temperature was raised to 43 degrees C, and reinitiated when cells were further incubated at this temperature.

Biochem J, 1980 Jun 1, 187(3), 905 - 8
Amino acid sequence around lipoic acid residues in the pyruvate dehydrogenase multienzyme complex of Escherichia coli; Hale G et al.; Amino-acid sequences around two lipoic acid residues in the lipoate acetyltransferase component of the pyruvate dehydrogenase complex of Escherichia coli were investigated . A single amino acid sequence of 13 residues was found . A repeated amino acid sequence in the lipoate acetyltransferase chain might explain this result.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3529 - 33
Evolution of a new enzymatic function by recombination within a gene; Hall BG et al.; Mutations that alter the ebgA gene so that the evolved beta-galactosidase (ebg) enzyme of Escherichia coli can hydrolyze lactose fall into two classes: class I mutants use only lactose, whereas class II mutants use lactulose as well as lactose . Neither class uses galactosylarabinose effectively . In this paper we show that when both a class I and a class II mutation are present in the same ebgA gene, ebg enzyme acquires a specificity for galactosylarabinose . Although galactosylarbinose utilization can evolve as the consequence of sequential spontaneous mutations, it can also evolve via intragenic recombination in crosses between class I and class II ebgA+ mutant strains . We show that the sites for class I and class II mutations lie about 1 kilobase, or about a third of the gene, apart in ebgA . Implications of these findings with respect to the evolution of new metabolic functions discussed.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3365 - 8
Two control regions for eukaryotic tRNA gene transcription; DeFranco D et al.; Two Drosophila tRNALys genes with identical coding sequences were shown to transcribe with very different efficiences in nuclear extracts from Xenopus oocytes . The use of recombinant plasmids in which the 5'-flanking sequences of these genes were either "switched" or replaced by defined pBR322 sequences revealed two control regions for tRNA gene transcription . An internal control region comprising the mature tRNA coding sequence (and possibly its 3'-flanking sequences) is sufficient for transcription initiation, and an external control region comprising the 5'-flanking sequences represses this transcription . All transcripts have short leader sequences . Altered precursor tRNAs transcribed from truncated tRNALys genes (missing a single base pair in the acceptor stem) are not processed well in vitro.

Vet Med (Praha), 1980 Jun, 25(6), 329 - 38
{The occurrence of O-antigens of Escheria coli strains in calves suffering from diarrhea in the Eastern Bohemian Region}; Svastova A; Coli infections in calves belong to the most serious diseases occurring in the early post-natal period and causing considerable losses to large cattle stocks . The calves affected by diarrhoea were studied as to the serological typification of E . coli . The total number of the calves examined was 1182 . The examination yielded 2112 isolated strains . Twelve antisera made it possible to identify 569 strains, i . e . 26.94 % . O-antigens were found to occur with the following descending frequency: 015, 0139, 0117, 0141, 08, 0149, 09, 0101, 02, 0147, 078, and 0115 . Although it is obvious that enteropathogenic strains of E . coli were not responsible for all cases of diarrhoea in the examined calves, the total set of animals was large enough to show which O-antigens could be involved in the diarrhoea in the calves kept on large cattle farms in the East Bohemian region.

J Bacteriol, 1980 Jun, 142(3), 869 - 78
Changes in cell diameter during the division cycle of Escherichia coli; Trueba FJ et al.; Extensive measurements of steady-state populations of several Escherichia coli strains have consistently indicated that cell diameter decreases with increasing cell length . This was observed both after electron microscopy of air-dried cells and after phase-contrast microscopy of living cells . The analysis was made by considering separately the unconstricted cells and three classes (slight, medium, and deep) of constricted cells in the population . During slow growth, cells with the average newborn length were up to 8% thicker than unconstricted cells twice as long . This decrease in diameter is less at higher growth rates . Despite the small changes and the large variation of the diameter in any particular length class, significant negative correlations between diameter and length were obtained . Cell diameter increases again at the end of the cell cycle as indicated by an increase of average diameter in the three consecutive classes of constriction.

J Bacteriol, 1980 Jun, 142(3), 1036 - 9
A mutant Ebg enzyme that converts lactose into an inducer of the lac operon; Rolseth SJ et al.; Lactose is not itself an inducer of the lac operon, nor is it converted to an inducer by ebg+ beta-galactosidase of Escherichia coli . We report here the isolation of a mutant Ebg beta-galactosidase which is capable of converting lactose into an inducer of the lac operon.

J Hyg (Lond), 1980 Jun, 84(3), 411 - 4
Studies on the enterotoxigenicity of environmental Escherichia coli, belonging to serotypes normally considered enterotoxigenic; Bettelheim KA et al.; Fifteen strains of Escherichia coli which had been collected in previous studies from animals and meat were studied . They belonged to serotypes considered enterotoxigenic and were examined for the production of the heat-labile and heat-stable enterotoxins . Only one of these strains (O8.Hnt) isolated from a cowpat in Cheshire produced heat-labile enterotoxin . Another strain (O8.H9) isolated from a cowpat in another part of Cheshire gave results suggesting production of small amounts of the heat-stable enterotoxin . The ecological aspects of these results are discussed.

Biokhimiia, 1980 Jun, 45(6), 1103 - 12
{Energy supply for transport of plasmid R 100-1 during conjugation of Escherichia coli cells}; Berzhinskene IaA et al.; It was shown that the transfer of plasmid R 100-1 during conjugation of donor and recipient cells of E . coli is suppressed under treatment of the cells by oxidative phosphorylation uncouplers . Studies on recipient cells devoid of their H+-ATPase activity due to mutation showed that the transfer of the plasmid into the cells is repressed after a switch-off of the respiratory chain, the only generator of proton motive force in the mutated cells . In the absence of arsenate the plasmid transfer from the donor into the recipient cells possessing intact H+-ATPase occurs independently of inhibition of the cell respiratory activity by cyanide . However, the presence of arsenate in the conjugation medium induces the sensitivity of the plasmid transfer process to cyanide . In the absence of cyanide the cell conjugation is suppressed by 60 mM arsenate . A kinetic study of different steps of cell conjugation showed that the generation of proton motive force in recipient cells is necessary for the occurrence of plasmid transport . It was assumed that the generation of both proton motive force and phosphorylated high energy compounds is a necessary prerequisite for plasmid transport during conjugation of donor and recipient cells.

J Gen Microbiol, 1980 Jun, 118(2), 405 - 10
Characterization of lambda cysB and of two derivatives carrying cysB amber mutations; Mascarenhas DM et al.; The specialized transducing phage lambda cysB (Borck et al., 1976) was found to carry about 5 kilobases of Escherichia coli DNA . It was shown to have an intact cysB gene but none of the known neighbouring genetic loci . The phage (which is known to be deficient in its site-specific recombination functions) was shown to integrate into the chromosome of bacterial recipients at the cysB locus . Excision from this site occasionally generated recombinant phages that had exchanged their cysB allele for the one originally present in the host . In this way lambda cysB derivatives were prepared from lysogens of two strains carrying the amber mutations cysB242 and cysB257; these phases were proved by several tests to contain the expected cysB amber mutations.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3322 - 6
Replication of duplex DNA of phage phi X174 reconstituted with purified enzymes; Arai K et al.; Replication of the covalently closed duplex replicative form (RF) of phage phi X174 DNA has been achieved by coupling two known enzyme systems: (i) synthesis of viral strand circles (SS) from RF, and (ii) conversion of SS to nearly complete RF (RF II) . In this coupled system, activated RF (gene A . RF II complex) was a more efficient template and generated as many as 10 RF II molecules per RF input, at a rate commensurate with SS synthesis . The 11 proteins required for the two component systems were all needed in the coupled RF duplication system; no new factors were required . Single-stranded DNA binding protein was needed for RF duplication at only 4% the level needed in its stoichiometric participation in SS synthesis . In addition to RF II, more complex replicative forms appeared late in the reaction, and their possible origin is discussed.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3225 - 9
Cleavage of the Escherichia coli lexA protein by the recA protease; Little JW et al.; The recA and lexA proteins of EScherichia coli are involved in a complex regulatory circuit that allows the expression of a diverse set of functions after DNA damage or inhibition of DNA replication . Exponentially growing cells contain a low level of recA protein, and genetic evidence suggests that lexA protein is involved in its regulation, perhaps as a simple repressor . Recent models for recA derepression after DNA damage have suggested that an early event in this process is the proteolytic cleavage of lexA protein, leading to high-level expression of recA . We present several lines of evidence that the specific protease activity of the recA protein, previously described with the lambda repressor as substrate, is capable of cleaving the wild-type lexA+ protein . First, lexA protein can be cleaved in vitro under the same conditions as prevously described for lambda repressor cleavage in a reaction requring both recA protease and ATP or an analogue, adenosine 5'-{lambda-thio}-triphosphate . Second, lexA protein can be observed in vivo as a physical entity after infection with lambda lexA+ transducing phage of host strains containing ittle or no active protease, but not in strains containing high levels of active protease . Finally, infection of host cells containing active protease with a lambda lexA+ transducing phage does not lead to repression of recA, but does so in cells lacking active protease . In all of these conditions the mutant lexA3 protein is largely resistant to inactivation or cleavage; this resistance can explain the dominant phenotype of lexA3 over lexA+ . We discuss models for recA derepression and re-establishment of repression which propose that modulation of the protease activity of recA protein regulates both of these transitions.

J Am Acad Dermatol, 1980 Jun, 2(6), 488 - 95
Systemic immune complex disease following intestinal bypass surgery: bypass disease; Utsinger PD; Twenty-one patients with arthritis and dermatitis following intestinal bypass surgery were studied . The arthritis was polyarticular, remittent, and intermittent . Typically, the synovial fluid was inflammatory . The commonest inflammatory skin lesion was a vesiculopustular dermatitis . Nineteen patients and serum immmune complexes using the Raji cell technic . Seventeen patients had serum cryoproteins, primarily consisting of IgG 1, IgG 3, C3, and C4 . Three patients had both Escherichia coli antigens and anti-E . coli antibody in their cryoprotein . Five patients had granular and one had linear deposits of immunoglobulin and complement at the dermoepidermal junction . Further evidence that bacterial antigens play a role in tissue injury was provided by detection of granular deposits of E . coli antigen at the dermoepidermal junctions in two patients, and at the glomerular capillary basement membrane in one patient.

Biull Eksp Biol Med, 1980 Jun, 89(6), 730 - 2
{Reaction between isolated lambda phage DNA and membrane structures of Escherichia coli cells}; Moiseeva TF et al.; The saccharose density gradient (30--55%) centrifugation technique applied to E . coli membrane preparations was used to show that treatment of the bacteria with Ca2+ in the cold results in the redistribution of the absorbed phage DNA from the cell wall to the cytoplasmic membrane while freezing-thawing of the bacteria leads to equal distribution of the infectious DNA among all membrane fractions . Quantitative estimation of such a redistribution is reported.

J Bacteriol, 1980 Jun, 142(3), 962 - 72
Construction and characterization of Escherichia coli polA-lacZ gene fusions; Ward DF et al.; The promoter of the polA gene of Escherichia coli K-12 was fused to the lacZ gene by selecting deletions within a lambda lacZ polA transducing phage . Four fusions, deleting varying amounts of the polA gene, were characterized . The polA promoter was found to be approximately 3% as active as the fully induced lac promoter . This figure is compatible with the normal intracellular level of deoxyribonucleic acid polymerase I . No evidence was found for outogenous regulation of transcription from the polA promoter . Expression from this promoter was influenced by neither recA nor mitomycin C, but uvrD and uvrE mutations reduced expression slightly.

J Bacteriol, 1980 Jun, 142(3), 768 - 76
Interaction of Escherichia coli adenosine triphosphatase with aurovertin and citreoviridin: inhibition and fluorescence studies; Satre M et al.; Aurovertins B and D inhibited the adenosine triphosphatase (ATPase) activity of soluble Escherichia coli coupling factor ATPase (BF1) isolated from wile-type E . coli K-12 . Half inhibition was obtained with 2 microns aurovertin B and 0.9 microns aurovertin D . Aurovertins B and D had no inhibitory effect on BF1 isolated from the aurovertin-resistant E . coli mutant MA12 . Acetylation or saponification of aurovertin D yielded a derivative which was devoid of inhibitory effect on BF1 . Citreoviridin also inhibited wild-type BF1 but with much less efficiency (half inhibition at 60 microns) than aurovertin . Citreoviridin had no effect on the aurovertin-resistant BF1 . The fluorescence intensity of aurovertins B and D was markedly enhanced upon addition to purified BF1 . There was no enhancement of fluorescence when the aurovertins were added to BF1 isolated from the aurovertin-resistant mutant . The fluorescence of the aurovertin-BF1 complex was enhanced by adenosine 5'-diphosphate and by low concentrations of adenosine 5'-triphosphate . The adenosine 5'-diphosphate-enhanced fluorescence of the aurovertin-BF1 complex was quenched by high concentrations of adenosine 5'-triphosphate or by MG2+ . Aurovertin bound selectively to the beta subunit of BF1 isolated from wile-type cells . By complementation assays in vitro, using a reconstituted system made of subunits isolated from wild-type and aurovertin-resistant BF1, it was shown that the altered peptide in aurovertin-resistant BF1 was the beta subunit.

Biokhimiia, 1980 Jun, 45(6), 979 - 91
{Nuclear translocation and effect of cAMP-dependent protein kinase on transcription}; Nesterova MV et al.; The influence of cAMP-dependent pig brain protein kinase and its subunits on transcription in vitro was studied . The increase in the template activity of chromatin isolated from the nuclei after treatment with the catalytic subunit was observed . The regulatory subunit of protein kinase was found to increase the number of binding sites for RNA polymerase on chromatin . The cAMP-dependent pig brain protein kinase was found to phosphorylate the sigma-factor of Escherichia coli RNA polymerase . This phosphorylation led to the increase of the RNA polymerase activity on phage lambda DNA . The nuclear translocation of the protein kinase and its subunits was shown to take place . In the cells with a low cAMP level (SV40 3T3) the transfer of the regulatory subunit to the nucleus was not detected . Only upon addition of cAMP and a subsequent formation of the cAMP-regulatory subunit complex, nuclear translocation was observed in these cells . The dependence of nuclear translocation of the cAMP-dependent protein kinase on cAMP level in the cell is proposed.

Int J Zoonoses, 1980 Jun, 7(1), 34 - 9
Studies on the examination of imported laboratory monkey, Macaca fascicularis for E . histolytica and other intestinal parasites; Sano M et al.; Infection rate of imported monkeys, under this study, with intestinal protozoa is higher than the infection rate with intestinal nematodes . Mostly encountered protozoa were E . coli, E . nana, E . histolytica and I . butschlii . Formalin-Ether concentration method yielded higher % positive for E . histolytica than the culture method using Tanabe-Chiba medium, but the results obtained from these 2 methods correlate perfectly well with each other . Efficacy of thiabendazole against intestinal nematodes such as Strongyloides, Trichuris, Physaloptera, Oesophagostomum and Capillaria was very satisfactory.

J Gen Microbiol, 1980 Jun, 118(2), 287 - 93
The gene-enzyme relationships of proline biosynthesis in Escherichia coli; Hayzer DJ et al.; A simple chromatographic procedure has been devised to separate gamma-glutamyl phosphate reductase and 1-pyrroline-5-carboxylate reductase, allowing the measurement of the former in crude Escherichia coli extracts . Analysis of a number of strains of E . coli has demonstrated that gene proA codes for gamma-glutamyl phosphate reductase and proB for gamma-glutamyl kinase . Introduction of a ColE1 hybrid plasmid containing the proA,B region into a strain with a chromosomal deletion of proA,B led to 3- and 17-fold increases in the specific activities of gamma-glutamyl kinase and gamma-glutamyl phosphate reductase, respectively.

Aust Vet J, 1980 Jun, 56(6), 279 - 84
Escherichia coli and rotavirus infections in four-week-old gnotobiotic piglets fed milk or dry food; Tzipori S et al.; A haemolytic enteropathogenic E . coli (WG) and pig rotavirus were isolated from a field case of postweaning diarrhoea in pigs . Four-week-old gnotobiotic piglets fed on milk diet were found to be extremely susceptible to infection with WG E . coli . Piglets were less susceptible to the infection immediately after the diet was changed from milk to dry food, and were almost completely resistant 4 days after the change to dry food . There was no difference in the clinical response to infection with WG E . coli when the piglets were fed either a high energy diet or low energy diet . Four-week-old piglets fed milk showed mild symptoms of diarrhoea when inoculated with pig rotavirus . Symptoms were more severe when piglets were inoculated immediately after the change from milk to dry food . Piglets inoculated 4 days after the change of diet showed no symptoms of diarrhoea at all . Under the conditions of these experiments the enteropathogenic E . coli produced a more serious disease than did pig rotavirus . Infection of 4-week-old gnotobiotic piglets with both agents given sequentially produced a diarrhoeal disease that was more severe than that produced by each agent separately.

Aust Vet J, 1980 Jun, 56(6), 274 - 8
Factors contributing to postweaning diarrhoea in a large intensive piggery; Tzipori S et al.; Some aspects of postweaning diarrhoea (PWD) in a piggery during the first week after early weaning were investigated . A haemolytic enterotoxigenic strain of E . coli (O149:K88:H10) was regularly recovered from piglets with PWD while rotavirus was demonstrated on a number of occasions . Prior to weaning piglets were either free of, or shed very few, haemolytic E . coli in their faeces . However, all piglets were excreting haemolytic E . coli between 5 and 7 days after weaning . The role of rotavirus in PWD was unclear . There appeared to be a direct relationship between serum antibodies to rotavirus in the slow at farrowing and those of the piglets soon after birth . The decline of maternal neutralising antibody to rotavirus coincided with the immediate postweaning period (3 to 5 weeks after birth) . This was followed by an increase in antibody levels, 5 to 8 weeks after birth . There was no significant difference in the growth rate between affected and unaffected piglets over a period of 120 days . Medication of water during the first week after weaning had no significant effect on the incidence of PWD in the herd . A change in both the weaner diet and the weaning procedure reduced piglet mortality associated with PWD by more than half.

J Antibiot (Tokyo), 1980 Jun, 33(6), 636 - 41
Action of streptothricin F on ribosomal functions; Haupt I et al.; The effect of streptothricin F on elongation factor-dependent and on elongation factor-free translation systems was studied . Streptothricin F inhibits factor-dependent as well as factor-free polypeptide synthesis . The results suggest that streptothricin F inhibits polypeptide synthesis via interaction with the ribosome . In partial reactions streptothricin F impairs EF-G-dependent translocation and to a lesser extent EF-Tu-dependent binding of aa-RNA to the ribosome, while it does not affect peptide bond formation significantly.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3686 - 90
Cloning of DNA complementary to the measles virus mRNA encoding nucleocapsid protein; Gorecki M et al.; Double-stranded cDNA synthesized from total poly(A)-containing mRNA, extracted from monkey cells infected with measles virus, has been inserted into Pst cleavage site of Escherichia coli plasmid pBR322 and cloned . A clone containing measles virus DNA sequences was identified by hybridization to a measles virus-specific 32P-labeled cDNA probe prepared from the mRNA of measles virus-infected cells . Cellular sequences in the probe were neutralized by prehybridization with an excess of unlabeled mRNA from uninfected monkey cells . The insert of cloned cDNA isolated contans 1420 base pairs, as shown by agarose gel electrophoresis and electron microscopy . The size of the mRNA complementary to this cloned cDNA is 1750 nucleotides, as determined by the reverse Southern technique . The cloned DNA fragment was further identified as the reverse transcript of the mRNA coding for the nucleocapsid protein of measles virus on the basis that the major cell-free translation product of mRNA selected by hybridization to the cloned DNA comigrated with the nucleocapsid protein and was immunoprecipitated by measles virus-specific antibodies . Subsequently, the cloned DNA was used to detect specific measles virus sequences in the poly(A)-RNA extracted from brain autopsy material from a patient with subacute sclerosing panecephalitis . The cloned DNA can thus be used as a probe to study the structure and expression of the measles genome, and in particular, to study diseases of the central nervous system in which persistent infection with measles virus has been implicated.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3590 - 4
Feedback regulation of ribosomal protein gene expression in Escherichia coli; Dean D et al.; The structural genes for Escherichia coli ribosomal protein (r-protein) genes L1, S4, and S11 were inserted into a plasmid vector containing the lac operator and promoter such that the synthesis of L1, S4, and S11 was controlled by lac regulatory elements . Synthesis of L1, S4, and S11 was stimulated by addition of an inducer of the lac operon (isopropyl thiogalactoside) to exponentially growing cells . Elevated synthesis of L1 caused a specific decrease in L11 synthesis, whereas overproduction of S4 resulted in lowered synthesis of S13 and L17 . Stimulation of L1 or S4 synthesis also inhibited cell growth . Overproduction of S11 did not affect synthesis of other r-proteins or alter growth . These results confirm previous in vitro studies {Yates, J . L., Arfsten, A . E . & Nomura, M . (1980) Proc . Natl . Acad . Sci . USA 77, 1837-1841} and support the hypothesis that certain r-proteins have the capacity to selectively inhibit synthesis of r-proteins whose genes are in the same operon as their own.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3581 - 5
Identification of 5-methylcytosine in DNA fragments immobilized on nitrocellulose paper; Sano H et al.; A method to identify 5-methylcytosine (m5Cyt) in DNA immobilized on nitrocellulose paper by using antibody against m5Cyt raised in rabbits is described . Immobilized restriction fragments of DNA are incubated first with purified antibody against m5Cyt and then with goat anti-rabbit IgG labeled with 125I . Restriction fragments containing m5Cyt are visualized by autoradiography . By using this method, a heavily methylated fragment of about 1700 base pairs was identified in nuclear DNA fom Chinese hamster cells, the methylation pattern of calf thymus satellite I DNA was examined, and chloroplast DNAs that were extracted from various stage of the Chlamydomonas life cycle were compared . Little if any methylation was detected in chloroplast DNA from vegetative cells or from male gametes, whereas homologous DNAs from female gametes and from zygotes were heavily methylated . The sensitivity of the method was examined with calf thymus satellite I DNA (which contains approximately 40 m5Cyt residues per repeat unit of 1400 base pairs) and with phi X174 virion DNA (which contains a single m5Cyt per molecule) . The presence of m5Cyt was detected with as little as 40 ng of phi X174 DNA containing 0.02 pmol of m5Cyt and with 100 ng of satellite DNA containing about 0.5 pmol of m5Cyt . Thus, the method makes possible the identification of individual methylated sites in purified DNAs in the size range of single genes.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3571 - 5
Intracisternal A-particle genes: identification in the genome of Mus musculus and comparison of multiple isolates from a mouse gene library; Lueders KK et al.; The genome of Mus musculus contains multiple copies (500 -1000) of DNA sequences related to the 35S RNA of intracisternal type A particles (IAPs) . Using labeled IAP RNA as a probe in blot-hybridization experiments, we have identified a characteristic electrophoretic pattern of reactive fragments generated by restriction endonuclease cleavage of mouse DNA . From the genomic blots, we deduced a composite restriction map for a 6.5- to 7-kilobase (kb) DNA region containing sequences homologous to the IAP RNA . Units of this type appeared to be interspersed without obvious regularity in nonhomologous flanking regions . A 5.2-kb segment of this unit was inserted directly into plasmid pBR322 from HindIII/EcoRI digest of mouse DNA . The fragment was cloned and then labeled by nick-translation and used to scan a mouse embryo gene library (average 16-kb inserts in lambda Charon 4A); 1% of the library samples hybridized, confirming the extensive reiteration of IAP genetic units . Among six different library isolates containing 6.5- to 7-kb IAP units, some restriction sites were highly conserved whereas others varied in both occurrence and position . Despite this variation, heteroduplexes between the individual isolates showed continuous IAP homology regions of 7 kb . No flanking region homologies were seen in this limited sample . Some evidence suggests that mouse DNA may contain other dispersed sequence elements related to but smaller than the genetic unit defined above.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3504 - 8
Biological activity of cloned Moloney sarcoma virus DNA: Terminally redundant sequences may enhance transformation efficiency; Blair DG et al.; We have measured the ability of cloned restriction fragments containing the whole and partial genomes of two strains of Moloney murine sarcoma virus to induce cell transformation in DNA transfection assays . The cloned intact ml and HTl murine sarcoma virus proviruses transform with an efficiency of approximately 40,000-50,000 focus-forming units/pmol of proviral DNA, and the majority of these transformed cells contain a rescuable viral genome . A cloned 2.1-kilobase-pair internal fragment of the murine sarcoma virus containing 1.2 kilobase pairs of sarcoma virus-specific sequences (src) and approximately 900 base pairs of leukemia virus-derived sequences adjacent to the 5' end of src transforms with approximately 1/10,000th the efficiency of the intact genome . When leukemia virus-deprived sequences containing a single copy of the 600-base-pair direct terminal repeated sequences are present at either the 5' or 3' end of this src-containing fragment, the transforming activity is stimulated 1000-fold . Cotransfection with a mixture of cloned fragments, one containing the internal 2.1-kilobase-pair src fragment and the other containing a single copy of the terminally redundant sequence, results in a 300-fold increase in transformation efficiency.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3369 - 73
Eukaryotic signal sequence transports insulin antigen in Escherichia coli; Talmadge K et al.; We made a series of plasmids with unique Pst restriction sites within or near the DNA that encodes the penicillinase signal sequence . Inserted DNA can be read in all three frames both within and immediately after the signal sequence . We cloned Pst-terminated DNA copies of the structural information for rat proinsulin and preproinsulin into these plasmids, forming a large number of hybrid penicillinase (bacterial) and insulin (eukaryotic) signal sequences . We then compared the levels of insulin antigen in the Escherichia coli periplasm with those inside the cells . We conclude that either the bacterial or the eukaryotic signal is sufficient to transport rat insulin antigen into the periplasmic space.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3346 - 50
The Escherichia coli L-arabinose operon: binding sites of the regulatory proteins and a mechanism of positive and negative regulation; Ogden S et al.; The locations of DNA binding by the proteins involved with positive and negative regulation of transcription initiation of the L-arabinose operon in Escherichia coli have been determined by the DNase I protection method . Two cyclic AMP receptor protein sites were found, at positions -78 to -107 and -121 to -146, an araC protein--arabinose binding site was found at position -40 to -78, and an araC protein-fucose binding site was found at position -106 to -144 . These locations, combined with in vivo data on induction of the two divergently oriented arabinose promoters, suggest the following regulatory mechanism: induction of the araBAD operon occurs when cyclic AMP receptor protein, araC protein, and RNA polymerase are all present and able to bind to DNA . Negative regulation is accomplished by the repressing form of araC protein binding to a site in the regulatory region such that it stimultaneously blocks access of cyclic AMP receptor protein to two sites on the DNA, one site of which serves each of the two promoters . Thus, from a single operator site, the negative regulator represses the two outwardly oriented ara promoters . This regulatory mechanism explains the known positive and negative regulatory properties of the ara promoters.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3307 - 11
Structure of Moloney murine leukemia viral DNA: nucleotide sequence of the 5' long terminal repeat and adjacent cellular sequences; Van Beveren C et al.; Some unintegrated and all integrated forms of murine leukemia viral DNA contain long terminal repeats (LTRs) . The entire nucleotide sequence of the LTR and adjacent cellular sequences at the 5' end of a cloned integrated proviral DNA obtained from BALB/Mo mouse has been determined . It was compared to the nucleotide sequence of the LTR at the 3' end . The results indicate: (i) a direct 517-nucleotide repeat at the 5' and 3' termini; (ii) 145 nucleotides out of 517 nucleotides represent sequences between the 5'-CAP nucleotide and 3' end of the primer tRNA (strong-stop DNA); (iii) an 11-nucleotide inverted repeat is present at the ends of the 5'-LTR and a total of 17 out of 21 nucleotides at the termini are inverted repeats; (iv) sequences CAATAAAAG (at positions -24 to -31) and CAATAAAC (at positions +46 to +53) resembling the hypothetical DNA-dependent RNA polymerase II promoter site can be identified in the 5'-LTR; (v) the sequence GAAA appears to be repeated on both sides of the junction of viral and cellular sequences; and (vi) in analogy with the bacterial transposons, the presence of an inverted repeat sequence at the termini of 5'-LTR suggests that M-MLV also has the integration properties of a transposon.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3149 - 53
Synthesis, cloning, and identification of DNA sequences complementary to mRNAs for alpha and beta subunits of thyrotropin; Vamvakopoulos NC et al.; Double-stranded cDNA sequences were synthesized, by using as templates mRNA for alpha and beta subunits of thyrotropin purified from mouse thyrotrophic pituitary tumours and cloned in Escherichia coli RR1 by insertion in the Pst I site of the bacterial plasmid pBR322 by use of poly(dA) x poly(dT) homopolymeric extensions . Plasmids containing inserted cDNA sequences were selected by resistance to tetracycline and sensitivity to ampicillin; those containing thyrotropin cDNA sequences were identified by colony hybridization with an 125I-labeled mixture of alpha and beta thyrotropin mRNAs . Plasmids carrying either alpha or beta thyrotropin cDNA sequences were further identified by hybridization to highly purified 125I-labeled alpha or beta thyrotropin mRNA, respectively . Two plasmids, one containing a 400-nucleotide alpha thyrotropin cDNA insert and the other containing a 710-nucleotide beta thyrotropin cDNA insert, were purified and characterized by restriction endonuclease digestions . Plasmid {32P}DNA containing either alpha or beta thyrotropin cDNA was then used as a hybridization probe for further characterization of alpha and beta thyrotropin mRNA from the mouse thyrotropic tumor . RNA was fractionated by agarose gel electrophoresis under denaturing and nondenaturing conditions and transferred to diazobenzyloxymethyl-paper . alpha thyrotropin mRNA of two sizes, 650 and approximately equal to 1500 nucleotides long, were identified . The larger alpha thyrotropin mRNA appeared to have marked secondary structure in its native form in contrast to the 650-nucleotide alpha thyrotropin mRNA . However, only one form of beta thyrotropin mRNA was detected with an apparent size of 710 nucleotides . We have successfully cloned and identified alpha and beta thyrotropin cDNA sequences in bacterial plasmids and used them to identify a second form of alpha thyrotropin mRNA.

Gene, 1980 Jun, 10(1), 75 - 8
Base distribution in the coding and noncoding regions in the rDNA of Lytechinus variegatus; Blin N et al.; The EcoRI restriction endonuclease cleaves rDNA repeat units of the sea urchin Lytechinus variegatus into four fragments . The G + C contents of all four cloned restriction fragments were determined by ispycnic analysis . Electron microscopic denaturation mapping of one of the fragments allowed alignment of the denaturation pattern with the restriction map and correlation with previously reported transcriptional data . From these results the base distribution in the spacer region and regions coding for rRNAs was derived.

Gene, 1980 Jun, 10(1), 69 - 73
A versatile primer for DNA sequencing in the M13mp2 cloning system; Heidecker G et al.; A primer for DNA sequencing by the chain-termination method in the M13mp2 cloning system was constructed and amplified . The primer was isolated as an EcoRI/AluI restriction fragment . After conversion of the AluI end into an EcoRI end the fragment was cloned in pBR325 from which it can be recovered by cleavage with EcoRI . The primer hybridizes to the single-stranded DNA of the mature M13mp2 phage next to the site of insertion thereby directing DNA synthesis along the inserted DNA.

Gene, 1980 Jun, 10(1), 39 - 46
Characterization of a site-specific restriction endonuclease SphI from Streptomyces phaeochromogenes; Fuchs LY et al.; A new type-II restriction endonuclease SphI, has been partially purified from Streptomyces phaeochromogenes . SphI recognizes the hexanucleotide sequence 5'-GCATGC and cleaves it at the position marked by the arrow . This nucleotide sequence is present twice in SV40 DNA, four times lambda DNA and only once in the cloning vehicles pBR322, pBR325, pBR327 and pBR328.

Can J Microbiol, 1980 Jun, 26(6), 718 - 21
Extracellular accumulation of L-glutamate in adenylyl cyclase deficient or cyclic AMP receptor protein deficient mutants of Escherichia coli; Leung KL et al.; An Escherichia coli cya mutant deficient in adenylyl cyclase and an E . coli crp mutant deficient in cyclic AMP receptor protein (CRP) accumulate substantial amounts of L-glutamate extracellularly when entering stationary phase of growth . The cya mutant grown in the presence of cyclic AMP accumulates little glutamate whereas the addition of cyclic AMP has no effect on glutamate accumulation in the crp mutant . It is proposed that an E . coli cell entering stationary phase requires a change in cell envelope structure which involes a cyclic AMP-CRP dependent process, and without this process the permeability of the cell membrane increases.

J Infect Dis, 1980 Jun, 141(6), 702 - 11
Disease due to enterotoxigenic Escherichia coli in Bangladeshi adults: clinical aspects and a controlled trial of tetracycline; Merson MH et al.; The clinical characteristics of disease due to enterotoxigenic Escherichia coli (ETEC) were determined in 88 adult males admitted to a hospital in Dacca, Bangladesh, with moderate to severe dehydration . Persons infected with ETEC strains producing both heat-labile toxin (LT) and heat-stable (ST) toxin had more dehydration and acidosis, longer duration of illness, and greater stool volume than persons infected with strains producing only ST . Tetracycline therapy, evaluated in 63 cases, resulted in slightly earlier termination of illness in patients with LT-ST strains but had no effect on illness in the patients with ST strains . In both groups of patients tetracycline shortened the duration of excretion of organisms . Because of its limited effectiveness and the generally excellent response of ETEC diarrhea to rehydration therapy alone, tetracycline is not warranted for use in treatment of ETEC diarrhea in adults in this population.

J Virol, 1980 Jun, 34(3), 675 - 83
Transcription of reconstituted simian virus 40 nucleoprotein complexes; Hidaka H et al.; The regulatory effects of host cellular histones on the transcription of simian virus 40 (SV40) DNA were investigated by using reconstituted and native SV40 nucleoprotein complexes (NPCs) . Reconstituted NPCs were prepared from SV40 DNA and the combination fraction of five histones, H1, H2A, H2B, H3, and H4, isolated from the nuclei of permissive (CV-1) or nonpermissive (BALB/c 3T3, rat liver, and calf thymus) cells . Native NPCs were prepared by alkali disruption of purified SV40 virions . Nuclease digestion of these NPCs gave regular patterns of bands similar to those of SV40 NPCs from SV40-infected CV-1 cells, suggesting the presence of a nucleosomal structure . Transcription of NPCs was analyzed in vitro by using Escherichia coli DNA-dependent RNA polymerase . Both histone H1 and the fraction consisting of all five histones inhibited transcription of SV40 DNA by about 90 to 95% . The fraction consisting of four histones lacking H1 reduced the transcription by 30 to 35%, to a level similar to that of transcription with native NPCs . Transcription was inhibited regardless of whether the origin of histones was permissive or nonpermissive cells . Gel electrophoretic patterns of RNA products transcribed from SV40 DNA and reconstituted and native NPCs showed several identical peaks between 13S and 28S . The patterns were identical whether NPCs reconstituted with H1 alone, all five histones, or four histones lacking H1 were used.

J Bacteriol, 1980 Jun, 142(3), 735 - 40
Permeability properties of Escherichia coli outer membrane containing, pore-forming proteins: comparison between lambda receptor protein and porin for saccharide permeation; Nakae T et al.; Outer membrane permeability conferred by lambda receptor protein and porins to maltose-maltodextrins and other oligosaccharides was studied in vitro with reconstituted vesicle membranes and in vivo with mutant strains lacking either one of these proteins . The vesicle membranes reconstituted from phospholipids, lipopolysaccharide, and purified lambda receptor allowed rapid diffusion of maltose and maltose-maltodextrins of up to six glucose residues, but the membranes acted essentially as a molecular sieve for sucrose, raffinose, stachyose, and inulins of molecular weights 800, 920, and 1,380 . The vesicle membranes containing porins allowed rapid diffusion of maltose but not of maltose-maltodextrins larger than maltose . The apparent transport Km values for maltose-maltodextrins of up to six glucose residues from the strain carrying lamB+ ompB (lambda receptor+, porin-) were similar (about 5 X 10(-6) M), whereas the transport Km values for maltose- and maltotriose of the strain carrying lamB ompB+ (lambda receptor-, porin+) alleles appeared to be 300 and about 20,000 X 10(-6) M . These results suggest that lambda receptor protein forms permeability pores that facilitate the diffusion of maltose-maltodextrins and function as a molecular sieve for other saccharides.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3360 - 4
A proton-coupled conformational switch of Escherichia coli 5S ribosomal RNA; Kao TH et al.; We report temperature-jump kinetic studies of the early melting transition of Escherichia coli 5S rRNA . A single measurable relaxation time tau, independent of concentration, was found at 266 nm . We monitored the transition temperature tm for this process (in the range from 0 to 40 degrees C) as a function of Mg2+, Na+, K+, spermidine, and H+ concentrations . Contrary to the usual effect of salts on nucleic acid stability, addition of mono- and multivalent counterions decreases tm for the early melting transition . Also unexpectedly, we found a strong dependence of tm on pH in the physiological range of 7--8 . Quantitative analysis of the data indicates that about 0.7 protons are release when the ordered (low-temperature) form melts, whereas about 2 NA+ (or K+) and 0.5 Mg2+ are taken up by the melted (high-temperature) form . We estimate the enthalpy of the transition to be 15--20 kcal/mol (63--84 kJ/mol) and also report the forward and reverse rate constants and activation energies for the transition, along with the influence of ions on the transition dynamics . Diffusion constant measurements reveal that the low-temperature form has a frictional coefficient about 10% larger than that of the high-temperature form . The data imply a low-temperature tertiary structure capable of binding a proton . Increase of pH, temperature, or counterion concentration (all at near-physiological values) causes a tertiary conformational switch to a more compact form that has greater counterion binding but less proton binding . We discuss possible physiological roles for the transition.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3331 - 5
Attenuation and processing of RNA from the rplJL--rpoBC transcription unit of Escherichia coli; Barry G et al.; Attenuation and processing of the mRNA from the ribosomal protein-RNA polymerase operon rplJL--rpoBC have been demonstrated by the analysis of nuclease SI-resistant RNA . DNA hybrids . These hybrids were formed between RNA produced in vivo and specific DNA restriction fragments which span the rplL--rpoB intercistronic region . The 3' end of the predominant attenuated RNA lies 69 nucleotides beyond the end of the rplL gene following sequence features that are similar to those of other known attenuators . The nonattenuated transcript is normally cleaved in the intercistronic region . However, in an RNase III mutant strain, the hybrids corresponding to the cleaved nonattenuated mRNAs disappear and the expected full-sized hybrid is seen . We have localized the cleavage to an area of possible secondary structure in the transcript approximately 200 nucleotides beyond the end of the rplL gene . This demontrates RNase III processing of Escherichia coli mRNA . The methods used in this study permit the examination of specific ends of large and complex polycistronic mRNAs . Such experiments should help in understanding how posttranscriptional events influence gene expression.

Proc Natl Acad Sci U S A, 1980 Jun, 77(6), 3196 - 200
Sequence of 1060 3'-terminal nucleotides of poliovirus RNA as determined by a modification of the dideoxynucleotide method; Kitamura N et al.; The dideoxynucleotide method for sequencing DNA developed by Sanger et al . {Sanger, F., Nicklen, S . & Coulson, A . (1977) Proc . Natl . Acad . Sci . USA 74, 5463-5467} was modified to allow sequence analysis of poliovirus RNA without recourse to cloning . Our method involves reverse transcription of poliovirus RNA followed by cDNA-dependent DNA synthesis in the presence of unlabeled dNTPs and 2',3'-dideoxynucleoside triphosphates, with Escherichia coli DNA polymerase I (Klenow) used to catalyze the reaction . DNA synthesis is primed by 5'-32P-labeled RNase T1- or RNase A-resistant oligonucleotides generated from poliovirus RNA . The sequence of 1060 nucleotides preceding the 3'-terminal poly(A) is presented . Based on the position of termination codons we propose that viral translation terminates at nucleotide -562.

Gene, 1980 Jun, 10(1), 53 - 61
Molecular cloning of DNA complementary to a mouse alpha-fetoprotein mRNA sequence; Law S et al.; DNA complementary to mouse yolk sac messenger RNA has been inserted at the PstI site of the plasmid pBR322 by annealing of the oligo(dG)-tailed plasmid DNA with the oligo(dC)-tailed mouse DNA . Transformation of Escherichia coli strain RRI with this annealed DNA yielded clones bearing recombinant plasmids . The clones were screened for DNA complementary to mouse alpha-fetoprotein (AFP) messenger RNA sequences by hybridization with a cDNA probe transcribed from an AFP mRNA of over 90% purity . Out of nine plasmids that were isolated and analyzed by restiction mapping, all had homologous insert DNA of various lengths . The plasmid with the longest insert, pAF6, contained 1.65 kb of added DNA, which is about 70% of the AFP mRNA . This clone was positively identified by a hybridization-translation procedure to contain a cDNA sequence for AFP . A restriction map of this clone and the orientation of the message are presented.

Gene, 1980 Jun, 10(1), 11 - 5
The nucleotide sequence of human fibroblast interferon cDNA; Taniguchi T et al.; DNA synthesized by in vitro reverse transcription of the interferon mRNA has been cloned and amplified as recombinant DNA, TpIF319-13 (Taniguchi et al., 1979) . The nucleotide sequence of this IF cDNA which consists of 770 bp (excluding the A:T tails) has been determined . The data reported predict the hitherto unknown amino acid sequence of human fibroblast interferon and its putative signal peptide.

Gene, 1980 Jun, 10(1), 1 - 10
The nucleotide sequence of a cloned human leukocyte interferon cDNA; Mantei N et al.; We have determined the nucleotide sequence of the human leukocyte interferon cDNA carried in hybrid plasmid Z-pBR322(Pst)/HcIF-2h, which has been shown to direct the formation of a polypeptide with human leukocyte interferon activity (Nagata et al., 1980) . The 910 base pair insert contains a 567 (or 543) base pair coding sequence, which determines a putative preinterferon polypeptide consisting of a signal peptide of 23 (or less likely 15) amino acids, followed by an interferon polypeptide of 166 amino acids (calculated molecular weight, 19 390) . The coding sequence is preceded by a (most likely incomplete) 56 bp leader and followed by a 242 bp trailer and seven A residues from the poly(A) tail: A comparison of the sequence of 35 amino terminal amino acids of lymphoblastoid interferon (Zoon et al., 1980; M . Hunkapiller and L . Hood, personal communication) and the corresponding sequence deducted for leukocyte interferon revealed 9 differences . This suggests that these two interferons are encoded by two non-allelic genes.

J Bacteriol, 1980 Jun, 142(3), 888 - 98
Control of protein synthesis in Escherichia coli: strain differences in control of translational initiation after energy source shift-down; Jacobson LA et al.; We have studied the parameters of protein synthesis in a number of Escherichia coli strains after a shift-down from glucose-minimal to succinate-minimal medium . One group of strains, including K-12(lambda) (ATCC 10798) and NF162, showed a postshift translational yield of 50 to 65% and a 2- to 2.5-fold increase in the functional lifetime of general messenger ribonucleic acid . There was no change in the lag time for beta-galactosidase induction in these strains after the shift-down . A second group, including W1 and W2, showed no reduction in translational yield, no change in the functional lifetime of messenger ribonucleic acid, and a 50% increase in the lag time for beta-galactosidase induction . Evidence is presented which indicates that this increased lag time is not the result of a decreased rate of polypeptide chain propagation . A third group of strains, including NF161, CP78, and NF859, showed an intermediate pattern: translational yield was reduced to about 75% of normal, and the messenger ribonucleic acid functional lifetime was increased by about 50% . Calculation of the relative postshift rates of translational initiation gave about 0.2, 1.0, and 0.5, respectively, for the three groups . There was no apparent correlation between the ability to control translation and the genotypes of these strains at the relA, relX, or spoT loci . Measurements of the induction lag for beta-galactosidase during short-term glucose starvation or after a down-shift induced by alpha-methylglucoside indicated that these regimens elicit responses that are physiologically distinct from those elicited by a glucose-to-succinate shift-down.

J Bacteriol, 1980 Jun, 142(3), 843 - 51
Temperature-induced synthesis of specific proteins in Escherichia coli: evidence for transcriptional control; Yamamori T et al.; Synthesis of several protein chains of Escherichia coli is markedly, though transiently, induced upon shift-up of a log-phase culture to or above the critical temperature (about 34 degrees C) . Such induction occurs coordinately for at least three protein chains (76K, 73K, and 64K) examined . Studies of initial kinetics of induction using a specific inhibitor of transcription (rifampin) revealed that induction occurs at the level of transcription with very little lag, though actual synthesis of messenger ribonucleic acids and proteins requires about 1 min when temperature is shifted up from 30 to 42 degrees C . Evidence suggests that E . coli cells somehow "recognize" the temperature change and activate transcription of several distinct operons, one of which contains the mop (morphogenesis of phages; groE) gene.

Gastroenterology, 1980 Jun, 78(6), 1545 - 53
In vitro antisecretory effects of trifluoperazine and other neuroleptics in rabbit and human small intestine; Smith PL et al.; The inhibitory effects of several neuroleptic agents on intestinal secretion were examined in vitro by measuring short-circuit current, net Cl flux, and cyclic nucleotide concentration, In rabbit ileal mu cosa, trifluoperazine (0.2-0.5 mM) did not significantly alter basal transport rates, but partially inhibited responses to the following secretagogues: theophylline, 8-Br-cAMP, VIP, dimethyl-PGE2 and heat-stable Escherichia coli enterotoxin (a cGMP agonist) . Trifluoperazine completely inhibited the response to Ca ionophore A23187 . In human small intestinal mucosa, trifluoperazine (0.1-0.5 mM) inhibited electrical responses to VIP and theophylline almost completely . The inhibitory action of trifluoperazine was manifest only on serosal addition . Trifluoperazine did not significantly alter cAMP or cGMP concentrations either under basal conditions or in the presence of secretagogues . It also did not diminish the electrical response to luminally added D-glucose . Three other neuroleptics were tested and found to have antisecretory action; the order of potencies were trifluoperazine greater than chlorpromazine greater than haloperidol greater chlorprothixene . Since all four agents are potent inhibitors of calcium-dependent regulator in bovine brain, this ubiquitous protein may also be the target for their antisecretory action in intestine.

Biochim Biophys Acta, 1980 May 30, 607(3), 457 - 69
Binding of Escherichia coli RNA polymerase to a specific site located near the 3'-end of the avaian sarcoma virus genome; Guntaka RV et al.; We have isolated a unique 35 base pair region of avian tumor virus DNA that binds specifically to Escherichia coli RNA polymerase holoenzyme . Studies with various size classes of viral DNA coupled with restriction enzyme mapping data indicate that the binding site is located in the large terminal repeat of the viral genome and is within the first 50 nucleotides of the heteropolymeric region corresponding to the 3'-end of the virion RNA.

Biochemistry, 1980 May 27, 19(11), 2522 - 8
Glucose 6-phosphate transport in membrane vesicles isolated from Escherichia coli: effect of imposed electrical potential and pH gradient; LeBlanc G et al.; Imposition of a membrane potential (delta psi, interior negative) or a pH gradient (delta pH, interior alkaline) across the membrane of Escherichia coli DF2000 leads to a marked, transient increase in glucose 6-phosphate transport that varies systematically with pH . Outwardly directed potassium diffusion gradients in the presence of valinomycin (i.e., generation of delta psi, interior negative) drive glucose 6-phosphate transport at pH 7.5 but much less effectively at pH 5.5, although the magnitudes of the transient delta psi generated are comparable at both pH values . Similarly, imposition of delta psi (interior negative) retards the rate of passive, carrier-mediated glucose 6-phosphate efflux down a concentration gradient at pH 7.5 but not at pH 5.5 . In contrast, imposition of delta pH (interior alkaline) by means of outwardly directed acetate diffusion gradients drives glucose 6-phosphate accumulation at pH 5.5 but is relatively ineffective at pH 7.5 . The results are independent of the pK of glucose 6-phosphate and provide strong support for the argument that the glucose 6-phosphate porter catalyzes an electrically neutral reaction at acid pH and an electrogenic reaction at alkaline pH . In addition, they are entirely consistent with the hypothesis that the proton/glucose 6-phosphate stoichiometry increases at alkaline pH {Rottenberg, H . (1976) FEBS Lett . 66, 159; Ramos, S., & Kaback, H.R . (1977) Biochemistry 16, 854, 4271}.

J Biol Chem, 1980 May 25, 255(10), 4660 - 6
DNA sequences from the str operon of Escherichia coli; Post LE et al.; The str operon at 72 min on the Escherichia coli chromosome contains genes for ribosomal proteins (r-proteins) S12 (str or rpsL) and S7 (rpsG) and elongation factors G (fus) and Tu (tufA) . The sequence of the entire S12 gene, the S12-S7 intercistronic region, and the beginning of the S7 gene is reported . Also, the sequence of the end of the S7 gene, the S7-G intercistronic region, and the beginning of the elongation fractor G gene is reported . The S12-S7 intercistronic region is 96 base pairs long, in contrast to other intercistronic regions in r-protein operons which have been found to vary from 3 to 66 base pairs . The S7-G intercistronic region is only 27 bases long, supporting the previous conclusion that r-protein and elongation factor genes are co-transcribed . A comparison of translation initiation sites of the S12 and S7 genes, and other examples of co-transcribed r-protein genes, reveals no obvious features that could account for equimolar synthesis of all r-proteins . The codon usage in the S12 and S7 genes follows the pattern observed in other r-protein genes; that is, there is a highly preferential usage of codons recognized by the most abundant of isoaccepting tRNA species . This pattern could reflect the cell's need for efficient translation or minimal errors, or both, in r-protein synthesis.

J Biol Chem, 1980 May 25, 255(10), 4603 - 6
Influence of "energization" on the binding of M protein with p-nitrophenyl alpha-D-galactopyranoside; Toci R et al.; A specific binding of p-nitrophenyl alpha-D-galactopyranoside has been measured by flow dialysis with Escherichia coli ML 308225 membrane vesicles containing the lac carrier protein . The number of binding sites, 0.45 nmol/mg of membrane protein, remains unchanged in the presence or absence of energy . On the other hand, "energization" increases the M protein affinity for p-nitrophenyl alpha-D-galactopyranoside . The dissociation constant (Kd) is 4 and 21 microM in the presence and absence, respectively, of D-lactate . The same energization effects are found with E . coli A3245 membrane vesicles . p-Nitrophenyl alpha-D-galactopyranoside can be used as a substrate to study energization effect on binding to the lactose permease M protein . These results corroborate observations that energy increases the lac carrier protein affinity for its substrate, and they also confirm the concentration of the M protein, which corresponds to 1.4% of the membrane protein.

J Biol Chem, 1980 May 25, 255(10), 4583 - 8
Aberrations of the classic codon reading scheme during protein synthesis in vitro; Samuelsson T et al.; Using a protein synthesizing in vitro system programmed with MS2-RNA, the ability of alanine tRNAs with the anticodons U*GC (U* represents 5-oxyacetic acid uridine monophosphate) and IGC to read the alanine codons in the coat protein cistron of MS2 has been determined both under conditions of no competition, where the alanyl-tRNA used was the only aminoacylated tRNAAla present in the system, and in experiments where the two alanyl-tRNAs were competing against each other . Under conditions of no competition, each of the anticodons can read all four alanine codons . However, when the anticodons compete for the codon GCC, the anticodon IGC, which can read all three positions of the codon according to the rules of Watson-Crick base pairing, is considerably more efficient than U*GC, which misreads the codon by reading only the first two positions and presumably disregards the third nucleotide of the codon . The outcome of the competition experiments also reveals two apparent violations of the wobble restrictions: the anticodon U*GC reads the codon GUU almost as effectively as does the anticodon IGC, and IGC is almost as effective as U*GC in reading the codon GCG.

J Biol Chem, 1980 May 25, 255(10), 4928 - 36
Transcription of simian virus 40 DNA by wheat germ RNA polymerase II . Priming of RNA synthesis by the 3'-hydroxyl of DNA at single strand nicks; Lewis MK et al.; Linear simian virus 40 DNA has been transcribed in vitro with wheat germ RNA polymerase II . Transcription products have been fractionated on polyacrylamide gels and several discrete sized RNA bands are seen . The RNA band pattern is affected dramatically by deoxyribonuclease treatment during RNA isolation . This is because most of the RNA synthesized is covalently linked to DNA . This linkage has been demonstrated by density analysis in formaldehyde-CsCl gradients and by incorporation of alkali-stable ribonucleotides into DNA . The linear DNA templates transcribed were generated by treatment of circular DNA with restriction enzymes which, in addition to cutting once at a single primary site, were found also to produce single strand nicks at specific secondary sites . The discrete sized RNA bands observed result from initiation at these nicks and terminated at DNA ends . There are two modes of nick-dependent initiation . In one mode the 3'-hydroxyl terminus of the DNA at a single strand nick serves as a primer for the extension of an RNA chain . In a second mode de novo initiation of an RNA chain is promoted at the nick . RNAs which are not primed initiate predominantly with GTP . The catalytic action of wheat germ RNA polymerase II is similar to that of Escherichia coli core RNA polymerase which has also been shown to synthesize primarily RNA which is covalently linked to DNA.

J Biol Chem, 1980 May 25, 255(10), 4854 - 63
A cloned chicken DNA fragment includes two repeated DNA sequences with remarkably different genomic organizations; Eden FC; The presence of both single copy sequences and repeated DNA sequences with a broad range of repetition frequency is a hallmark of the eukaryotic genome . The advent of recombinant DNA technology has made it possible to isolate cloned DNA fragments that encompass two or more DNA sequences with different repetition frequencies . This provides the first opportunity to investigate the structural relationships in the genome of DNA of the different repetition frequency classes in a thorough and systematic way . A cloned fragment of the chicken genome containing two different repeated DNA sequences has been used for this purpose . By hybridization of radioactive restriction fragments of the cloned DNA to filter-bound restriction fragments of total chicken DNA, it has been determined that the 5.5-kilobase inserted DNA in this clone contains a copy of each of two long, repeated DNA sequence elements with different repetition frequencies . These two repeated DNA sequences have very diverse arrangements in the chicken genome . The results establish that, in addition to the interspersion of single copy and repeated DNA sequences in the chicken genome, repeated DNA sequences with very different structural characteristics can be interspersed with one another . Thus, the chicken genome is a complex network of related sequences in which some members of a family of repeated DNA sequences are associated with other, nonhomologous repeated DNA sequences, while other members of the same family are flanked by single copy DNA.

J Biol Chem, 1980 May 25, 255(10), 4653 - 59
DNA sequence of the promoter region for the alpha ribosomal protein operon in Escherichia coli; Post LE et al.; Previous studies showed that the gene for RNA polymerase subunit alpha at 72 min on the Escherichia coli chromosome is co-transcribed with genes for ribosomal proteins (r-proteins) S11, S4, and L17, and probably S13 . DNA sequence analysis of a deletion mutant has now established that the S13 gene is a part of the alpha operon and the gene order is promoter (P alpha), rpsM (S13), rpsK (S11), rpsD(S4), rpoA(alpha), and rplQ(L17) . The DNA sequence extending 650 bases before S13 gene was determined . In vitro transcription experiments establish the probable location of the alpha promoter (P alpha) within this sequence . The start site is 94 nucleotides upstream from the initiation codon (GUG) of the S13 gene . This promoter has features previously noted as common to E . coli promoters . However, comparison with four other sequenced promoters of r-protein operons shows no unique common features that might account for the common regulation of synthesis of r-proteins . This lack of sequence similarity in promoters of r-protein operons may be because r-protein synthesis is regulated at least partially at a post-transcriptional level.

Nucleic Acids Res, 1980 May 24, 8(10), 2225 - 40
A rapid enzymatic DNA sequencing technique: determination of sequence alterations in early simian virus 40 temperature sensitive and deletion mutants; Seif I et al.; We have adapted a rapid sequencing technique from the enzymatic nick-translation method of Maat and Smith . The Forward-Backward procedure employs both synthetic and 3' to 5' exonucleolytic activities of E . coli DNA polymerase I to achieve greater reliability, especially in reading stretches of the same nucleotide . The technique has been employed to determine sequence alterations in four early SV40 temperature-sensitive (tsA) point mutants and five early SV40 viable deletion mutants . The nucleotide sequence of these mutants provides an insight into their biological properties.

Nature, 1980 May 22, 285(5762), 207 - 10
Isolation of the chicken thymidine kinase gene by plasmid rescue; Perucho M et al.; We have used the bacterial plasmid pBR322 as a vehicle to isolate genes coding for selectable markers from higher eukaryotes . In this way, we have obtained the chicken thymidine kinase (tk) gene as a 2.2-kilobase EcoRI/HindIII insert in BR322 . The cloned gene transforms tk- animal cells with an efficiency equal to that of the cloned herpes simplex virus-1 tk gene.

Biochem J, 1980 May 15, 188(2), 467 - 73
Quantitative analysis of proton-linked transport system . beta-Galactoside exit in Escherichia coli; Booth IR et al.; The exit of lactose and thiomethyl-beta-D-galactoside from Escherichia coli ML308-225 has been studied to determine the role of carrier-dependent (zero-trans efflux) and carrier-independent (leak) processes . On the basis of its sensitivity to p-chloromercuribenzene sulphonate the exit of lactose was found to be almost wholly mediated by the carrier . Consistent with this conclusion was the finding that the rate of exit of this sugar was dependent on the external pH, being considerably slower at acid pH . On the other hand exit of thiomethyl-beta-D-galactoside was found to be composed of both carrier-dependent and carrier-independent processes . Both processes exhibited first-order kinetics with the rate constants for zero-trans efflux and leak being 0.137 min-1 and 0.079 min-1, respectively . The relevance of these findings for out earlier proposal for the methods of attenuation of solute accumulation is discussed {Booth, Mitchell & Hamilton (1979) Biochem . J . 182, 687--696}.

Biochem J, 1980 May 15, 188(2), 345 - 50
The role of the membrane-bound hydrogenase in the energy-conserving oxidation of molecular hydrogen by Escherichia coli; Jones RW; H2-dependent reduction of fumarate and nitrate by spheroplasts from Escherichia coli is coupled to the translocation of protons across the cytoplasmic membrane . The leads to H+/2e- stoicheiometry (g-ions of H+ translocated divided by mol of H2 added) is approx . 2 with fumarate and approx . 4 with nitrate as electron acceptor . This proton translocation is dependent on H2 and a terminal electron acceptor and is not observed in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone and the respiratory inhibitor 2-n-heptyl-4-hydroxyquinoline N-oxide . H2-dependent reduction of menadione and ubiquinone-1 is coupled to a protonophore-sensitive, but 2-n-heptyl-4-hydroxy-quinoline N-oxide-insensitive, proton translocation with leads to H+/2e- stoicheiometry of approx . 2 . H2-dependent reduction of Benzyl Viologen (BV++) to its radical (BV+) liberates protons at the periplasmic aspect of the cytoplasmic membrane according to the reaction: H2 + 2BV++ leads to 2H+ + 2BV+ . It is concluded that the effective proton translocation observed in the H2-oxidizing segment of the anaerobic respiratory chain of Escherichia coli arises as a direct and inevitable consequence of transmembranous electron transfer between protolytic reactions that are spatially separated by a membrane of low proton-permeability.

Biochemistry, 1980 May 13, 19(10), 2085 - 9
Primary structure of AUA-specific isoleucine transfer ribonucleic acid from Escherichia coli; Kuchino Y et al.; The nucleotide sequence of an E . coli isoleucine tRNA (tRNAIle minor) specific for the codon AUA was determined by postlabeling procedures using only 2.5 micrograms (0.05 A260 unit) of the material . The sequence was pG-G-C-C-C-C-U-s4U-A-G-C-U-C-A-G-U-Gm-G-D-D-A-G-A-G-C-A-A-G-C-G-A-C-U-N+-A-U-t6A-A-psi-C-G-C-U-U-G-m7G-acp3U-C-G-C-U-G-G-T-psi-C-A-A-G-U-C-C-A-G-C-A-G-G-G-G-C-C-A-C-C-AOH . The nucleotide sequences in the regions of the D arm and T psi C arm of tRNAIle minor were quite similar to the corresponding regions of tRNAIle major . However, the sequences in the CCA stem and anticodon stem of tRNAIle minor were different from those of tRNAIle major . The overall homology between the two isoleucine tRNAs was 68% . E . coli tRNALys, tRNAMet, tRNAValIIA and tRNAArg also have relatively high sequence homology with tRNAIle minor.

J Biol Chem, 1980 May 10, 255(9), 4381 - 5
A comparative study of the thermal inactivation of the isolated and associated domains within the beta 2 subunit of Escherichia coli tryptophan synthetase . Evidence for strong interdomain interactions; Zetina CR et al.; The irreversible inactivation by heat of the F1 and F2 regions of the beta 2 subunit of Escherichia coli tryptophan synthetase (L-serine hydrolyase (adding indole) EC 4.2.1.20) has been studied . By comparing the kinetics of inactivation of the F1 and F2 fragments, either isolated by proteolysis or associated within the beta 2 protein, it is shown that the F1 fragment is protected considerably against heat inactivation by its interactions with the complementary F2 fragment . An important stabilization of the protein conformation by the coenzyme, pyridoxal 5'-phosphate, is also observed . By using a hybrid enzyme preparation, it is shown that the stabilization by a single pyridoxal 5'-phosphate molecule of the two protomers within beta 2 is likely to be caused by a strengthening of interdomain interactions upon binding of the coenzyme . These results point to a strong energetic coupling between the two domains of the beta chain.

J Biol Chem, 1980 May 10, 255(9), 3838 - 40
Accumulation of ppGpp in a relA mutant of Escherichia coli during amino acid starvation; Torok I et al.; In Escherichia coli, amino acid starvation triggers the rapid synthesis of two guanosine polyphosphates, pppGpp and ppGpp (the 3'-pyrophosphates of GTP and GDP, respectively) . Determination of the turnover rate of the ppGpp pool indicated that during serine deprivation, as opposed to other amino acid starvations, the rate of ppGpp degradation is dramatically decreased . This results in a slow but significant accumulation of this regulatory nucleotide in a relA mutant during serine starvation . Similar ppGpp accumulation can be seen during serine starvation in different serine auxotrophic mutants carrying different relA alleles . On the other hand, no ppGpp accumulation is induced in various relaxed strains by serine hydroxamate treatment.

Nucleic Acids Res, 1980 May 10, 8(9), 1933 - 45
Nucleotide sequences at the ends of the mercury resistance transposon, Tn501; Brown NL et al.; The nucleotide sequences at the ends of the mercury-resistance transposon, Tn501, have been determined . The terminal sequences are inverted repeated sequences 38 nucleotide pairs in length, which differ in 3 nucleotide pairs . The transposon is flanked by directly repeated sequences of 5 nucleotide pairs, originating from a single pentanucleotide sequence in the recipient replicon . There is no obvious homology between recipient replicons at the site of insertion of the transposon . The structures of the ends of Tn501 are compared with those of other transposons and insertion sequences . The use of Tn501 to locate an EcoRI site within a genetically defined sequence of interest is discussed.

Nucleic Acids Res, 1980 May 10, 8(9), 2085 - 91
Structure of transfer RNA by carbon NMR: resolution of single carbon resonances from 13C-enriched, purified species; Agris PF et al.; Methyl carbon-13 NMR spectra of purified tRNA species are presented for the first time . In addition, these spectra of tRNA species specific for phenylalanine, tyrosine, and cysteine exhibited the first resolution of single methyl carbon resonances . Carbon-13 enriched methyl groups of ribothymidine (T) and 7-methylguanosine (m7G) and the methylthio group of 2-methylthio-N6-(delta2-isopentenyl) adenosine (ms2i6A) were resolved . The T methyl signal of tRNAPhe shifted from 12.3 ppm at 45 degrees in the absence of added Mg2+ to 11.1 ppm at 30 degrees in the presence of 10mM MgCl2 . The same change in conditions led to a 0.4 ppm shift of the m7G methyl signal in the opposite direction . The relative ease in obtainment of single carbon resonances of purified tRNA species, and display of the sensitivity of their chemical shifts to changes in local structure, are requisite criteria for 13C-NMR to be a useful technique in probing tRNA conformation and its changes during interaction with proteins and other nucleic acids.

Nucleic Acids Res, 1980 May 10, 8(9), 2023 - 37
Two kinetically distinct tRNAile isoacceptors in Escherichia coli C6; Harris CL et al.; The isoleucine acceptance of tRNA from Escherichia coli C6 was previously shown to be influenced by the synthetase level (Marashi, F . and Harris, C.L . 1977 . Biochim . Biophys . Acta 477, 84-88) . We show here that the increased acceptance observed at higher enzyme levels is accompanied by an increase in the aminoacylation of one tRNAile species . Hence, tRNAile, a minor species at low enzyme levels, is a major isoacceptor after full aminoacylation . The two major isoleucine species have been purified using a combination of BD-cellulose, DEAE-Sephadex A-50 and methylated albumin kieselguhr chromatography . tRNAile (1511 pmoles ile/A260 of tRNA) was found to be slowly acylated, with 2a Vmax one-seventh that observed with tRNAil3le (1475 pmoles ile/A260) . Two-dimensional TLC analysis of RNase T2 digests revealed differences in nucleotide content between the purified tRNAs . These results are discussed in terms of the presence of slow and fast tRNAile species in E . coli.

Clin Chim Acta, 1980 May 9, 103(3), 287 - 95
Measurement of fibrinogen degradation products by a sandwich enzyme immunoassay technique; Tanaka M et al.; We describe a highly sensitive enzyme immunoassay technique using beta-D-galactosidase from Escherichia coli as a label to quantify fibrinogen and its degradation products . The minimum detectable concentrations of fibrinogen, fragment D and fragment E, were 0.6, 0.06 and 0.2 ng/ml of reaction mixture, respectively . The cross-reactions of the assay-system for fragment E with fibrinogen and fragments X, Y and D were 5, 8, 56 and 0% respectively . The assay system for fragment D did not cross-react with fragment E, but did cross-react with fragments X, Y and fibrinogen (38, 10 and 15% respectively) . Fractionation of the serum sample on Sephadex G-200 column allowed specific quantification of fragments D and E in serum samples.

Nature, 1980 May 8, 285(5760), 78 - 81
Mutations which alter the function of the signal sequence of the maltose binding protein of Escherichia coli; Bedouelle H et al.; The maltose binding protein of Escherichia coli is secreted into the external periplasmic compartment of the cell by virtue of an amino-terminal signal sequence . Using DNA sequencing, we have determined the precise nature of mutations in the signal sequence which prevent the export of the maltose binding protein, causing it to accumulate in the cytoplasm in its precursor form . In most cases, the change of a single hydrophobic or uncharged amino acid to a charged amino acid within the signal sequence is sufficient to block the secretion process.

Nature, 1980 May 8, 285(5760), 82 - 5
Sequence analysis of mutations that prevent export of lambda receptor, an Escherichia coli outer membrane protein; Emr SD et al.; The amino-terminal signal sequence is required for initiation of transmembrane protein transfer of the Escherichia coli lambda receptor protein . Mutations leading to insertion of charged amino acids into or deletion of amino acids from the hydrophobic segment of this sequence prevent export of this outer membrane protein.

J Cell Physiol, 1980 May, 103(2), 217 - 37
Differential expression of lectin receptors during hemopoietic differentiation: enrichment for granulocyte-macrophage progenitor cells; Nicola NA et al.; Molecular changes occur at the surface of hemopoietic cells during differentiation from progenitor cells to mature granulocytes and macrophages . The differential expression of surface carbohydrate residues has been probed using lectins and the results used to purify normal mouse granulocyte-macrophage progenitor cells . Ten different lectins were screened for selective interaction with mouse hemopoietic colony-forming cells (CFCs), using agglutination or a quantitative analysis of the number of fluoresceinated lectin molecules bound per cell using a fluorescence activated cell sorter (FACS) . Pokeweed mitogen (PWM), Helix pomatia agglutinin (HPA), soybean agglutinin (SBA), and peanut agglutinin (PNA) preferentially bound to CFCs so that it was possible to enrich 4 to 10-fold for these progenitor cells by sorting for the highly fluorescent cells . Further analysis of the low and high angle light scattering characteristics of the CFCs indicated that these cells were polydisperse, but could be enriched ten-fold by selecting for cells with high intensity low angle (0 degrees) scatter and low intensity high angle (90 degrees) scatter . PWM gave the best enrichment (10 to 15-fold) for adult bone marrow CFCs, for CFCs from fetal sources (fetal liver, fetal blood), and for CFCs from the spleens of mice injected previously with outer membrane lipoprotein from E . coli . Three parameter sorting for CFC using the FACS (low angle scatter, high angle scatter, and PWM-fluorescence) resulted in large enrichment factors (16 to 50-fold) for CFCs from all the above sources . Over 7% of the cells sorted from bone marrow, 10% of the cells sorted from post-lipoprotein spleen, and 28% of the cells sorted from fetal peripheral blood were hemopoietic CFCs . Ninety percent of the cells in these fractions had the morphology of blast cells or myelocytes . Thus, it was possible to identify the morphological characteristics of the hemopoietic progenitor cells . Screening of other developmental systems using quantitation of fluorescence with lectins should prove of general value for the purification of selected differentiation states.

Mol Biol (Mosk), 1980 May-Jun, 14(3), 650 - 60
{Cloning in Escherichia coli cells of mouse DNA fragments homologous to two main species of long hairpin regions of pre-mRNA}; Kramerov DA et al.; Clones of plasmid pBR322, containing fragments of mouse DNA were obtained . DNA from many of these clones (at least 15%) was able to hybridize with double-stranded hairpin-like regions of pre-mRNA (dsRNA-B) . It was shown by hybridization of dsRNA-B with clone DNA, that there are two abundant species of sequences in the population of these molecules designated as B1 and B2 . They are 40-50% and 20-25% of all the molecule of dsRNA-B, respectively . The size of DNA sequences complementary to dsRNA is about 200--400 base pairs . The melting experiments with hybrids show that the members of B1 family are very similar if not identical, while the divergence among B2 sequences is higher but still the number of substitutions does not exceed 10% of bases . The sequence B1 and B2 are represented by many copies in the mouse genome and in pre-mRNA, and many of them probably do not form hairpin-like structures.

Cell, 1980 May, 20(1), 223 - 35
Homologous pairing in genetic recombination: recA protein makes joint molecules of gapped circular DNA and closed circular DNA; Cunningham RP et al.; The recA protein, which is essential for genetic recombination in E . coli, promotes the homologous pairing of double-stranded DNA and linear single-stranded DNA, thereby forming a three-stranded joint molecule called a D loop . Single-stranded DNA stimulates recA protein to unwind double-stranded DNA . By a presumably related mechanism, recA protein promoted the homologous pairing of two circular double-stranded molecules when one of them has a gap in one strand . The two molecules were joined at homologous sites by noncovalent bonds . The covalently closed molecule remained intact and was not topologically linked to the intact circular strand of the gapped substrate . Electron microscopy showed that molecules were usually linked at two or more nearby points . The junctions in most molecules were shorter than 300 nucleotides . Sometimes the region between two extreme points was separated into two arms, producing an ellipsoidal loop (called an eye loop) . The junctions in these biparental joint molecules were frequently remote from the site of the gap . We infer that a free end of the interrupted strand crosseover to form a structure like a D loop which moved away from the gap by branch migration.

Chem Biol Interact, 1980 May, 30(2), 189 - 201
The electronic structure of platinum-guanine complexes; Carsey TP et al.; Molecular orbital calculations using the SC-MEH method have been carried out on guanine and its mode of interaction with the anti cancer drug,cis-diamminodichloroplatinum(II) (DDP), in various geometrical bonding conformations . It is shown that if indeed a monomeric complex between DDP and guanine is formed, the N-7 and O-6 positions of guanine bond most strongly with DDP in both monodentate and bidentate chelation models . The influence of this bonding on the N-1--H-1 bond is studied in terms of atomic charge variations and orbital overlap population densities to determine if miss-pairing in DNA might occur via the loss of the guanine H-1 proton, as proposed in the mechanism of O-6 methylation . Preliminary findings do not support one of the proposed mechanisms for miss-pairing in DNA if a bidentated N-7, O-6 DNA-DDP chelate is formed . Interest in the cellular effects of square-planar platinum complexes began with Rosenberg's discovery in 1965 that DDP, inhibited cell division with inhibiting growth rate in Escherichia coli bacteria {u} . Shortly thereafter, the anti-cancer activity of DDP and a number of related platinum complexes was demonstrated {2} . Since then, DDP has been used effectively for a number of types of cancers including lung, head and neck, prostate, bladder, ovaran, and testicular cancers {3}, and has recently been released in the United States for distribution as a prescribed drug in chemotherapy.

Vopr Med Khim, 1980 May-Jun, 26(3), 291 - 301
{Superoxide dismutase--radiobiologic significance and possibilities (review)}; Gusev VA et al.; Modern data are considered on the importance of superoxide radical in the oxygen effect of ionizing radiation as well as the participation of superoxide dismutase in biological radioresistance . Biological role and some physico-chemical properties of the enzyme are described . Estimation of the superoxide dismutase activity might serve as a test for study of the primary effect of ionizing radiation on cells; at the same time, the enzymatic preparations could be used as radioprotective drugs.

Prikl Biokhim Mikrobiol, 1980 May-Jun, 16(3), 351 - 5
{Conditions of the synthesis of lysine decarboxylase by Escherichia coli MRE 600}; Beretskene SIa et al.; The effect of aeration, pH of the cultivation medium, temperature and time of cultivation of Escherichia coli MRE600 on the synthesis of cellular lysine decarboxylase (LDC) was studied . It was demonstrated that LDC reached maximum activity in the 5-hour bacterial culture cultivated in the nutrient medium with pH 6.0 at 29--30 degrees C . Aeration increased the yield by about 3 times and decreased LDC activity by 5.5 times.

Genetics, 1980 May, 95(1), 15 - 38
Mapping of the polA locus of Escherichia coli K12: genetic fine structure of the cistron; Kelley WS; The close linkage of the glnA gene with polA was exploited to construct a fine structure map of polA by means of generalized transduction with phage P1 . Nine different polA- alleles were mapped by recombinational crosses . The results indicate a gene order consistent with previous observations (KELLEY and GRINDLEY 1976a; MURRAY and KELLEY 1979) . Three mutations, polA5, polA6 and polA12 map within the "carboxy-terminal" or "large-fragment" portion of the gene in unambiguous order . Four alleles, known to affect the "amino-terminal" portion of the gene, polA107, polA214, polA480ex and polA4113, appear to be closely linked with certain ambiguities in their exact order . All four of these mutations are known to alter the 5' leads to 3' exonuclease activity of DNA polymerase I and three of them result in the conditional lethal polA- phenotype . The polA1 nonsense mutation maps between these two groups in a position consistent with its known effect, production of an amber fragment that includes the 5' leads to 3' exonuclease . The final allele, resA1, is another nonsense mutation that maps at the extreme "amino-terminus" of the cistron.----A number of control experiments were conducted to determine the effects of polA- mutations on the P1-mediated recombinational event . These experiments indicated that abortive transduction occurs quite frequently, but the formation of abortive transductants and segregation of unselected transduced markers among daughter progeny is like that observed by other investigators . There was no evidence that any individual polA- allele behaved in an exceptional fashion during recombination.

J Gen Microbiol, 1980 May, 118(1), 253 - 61
Phenotypic stability of trp operon recombinant plasmids in Escherichia coli; Imanaka T et al.; The recombinant plasmids RSF2124-trp and pSC101-trp were examined for their phenotypic stability in Escherichia coli W3110 and its derivatives under various culture conditions . RSF2124-trp and pSC101-trp were stable in a trpAE1 strain . In an amber mutant of the tryptophan repressor gene, RSF2124-trp was fairly stable, whereas pSC101-trp was unstable . All Trp- segregants from the pSC101-trp carrier had lost the entire plasmid . In a mutant carrying the tnaA mutation, RSF2124-trp was unstable in rich media . Most Trp- segregants that appeared under these conditions were deleted in trp genes as well as in the cI gene on the recombinant plasmid . pSC101-trp in this tnaA mutant was also unstable . All Trp- segregants had lost the plasmid . Studies of enzyme activities revealed that the greater the activity of anthranilate synthase and tryptophan synthase in bacteria, the more segregants tended to appear in the stability test . RSF2124 and pSC101 without the trp gene were completely stable in the same bacteria . The apparent instability of bacteria carrying the recombinant plasmid could be explained by the lower growth rate compared with bacteria carrying only the vector plasmid, resulting in the enrichment of Trp- bacteria during culture.

J Gen Microbiol, 1980 May, 118(1), 107 - 13
Evidence for two adhesive antigens on the K99 reference strain Escherichia coli B41; Morris JA et al.; Immunoelectrophoresis and haemagglutination studies with a K99 antigen extract from the reference strain Escherichia coli B41 (O101:K99) demonstrated both anionic and cationic mannose-resistant haemagglutinins for horse red blood cells . Neither haemagglutinin was produced by bacteria grown at 18 degrees C . Antibodies to the cationic haemagglutinin were demonstrated in antisera to all the K99-positive E . coli strains in every serogroup examined, but antibodies to the anionic haemagglutinin were only detected in antisera to E . coli strains from the O9 and O101 serogroups . Inhibition of E . coli B41 adhesion to calf brush borders and indirect immunofluorescent staining indicated that the anionic haemagglutinin also exhibited adhesive properties.

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