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 associat