J Biol Chem, 1979 Nov 10, 254(21), 10803 - 10 A synthetic tyrosine suppressor tRNA gene with an altered promoter sequence . Its cloning and relative expression in vivo; Ryan MJ et al.; The total synthesis of a tyrosine suppressor tRNA gene with a modified promoter is described . The alteration involves the replacement of the four G:C base pairs immediately preceding the start point of transcription by A:T base pairs . The new sequence contains the recognition sequence for the HindIII restriction endonuclease at the transcriptional start point, thus permitting fusion of the structural gene with promoters containing independent sequence modifications . The construction, cloning, and biological activity of several recombinant DNAs containing the tRNA gene with the modified promoter are described . The expression of this gene in vivo is compared with that of both the unmodified synthetic suppressor gene and a naturally occurring tyr su3+ gene cloned onto a multicopy plasmid. J Biol Chem, 1979 Nov 10, 254(21), 10604 - 6 Nucleotide sequence of the intercistronic region preceding the gene for RNA polymerase subunit alpha in Escherichia coli; Post LE et al.; The gene for RNA polymerase subunit alpha is a co-transcribed with several ribosomal protein genes (Jaskunas, S.R., Burgess, R.R., and Nomura, M . (1975) Proc . Natl . Acad . Sci . U.S.A . 72, 5036-5040) . The DNA sequence whicch codes for the COOH-terminal amino acids of S4 and the NH2-terminal amino acids of alpha, and the 25 nucleotide intercistronic sequence have been determined . This short distance supports the idea that some post-transcriptional regulation determines the differential synthesis of alpha and ribosomal proteins. J Biol Chem, 1979 Nov 10, 254(21), 10846 - 52 Paraquat and Escherichia coli . Mechanism of production of extracellular superoxide radical; Hassan HM et al.; Paraquat mediates a superoxide dismutase-inhibitable reduction of cytochrome c by suspensions of Escherichia coli B . Glucose was most effective in providing electrons for this cytochrome c reduction, but other nutrients could serve in this capacity, provided the cells were preconditioned by growth on these nutrients . Paraquat reduction depended upon a NADPH:paraquat diaphorase, present in the cytosol . Reduced paraquat could diffuse across the cell envelope and react with dioxygen, in the suspending medium, thus generating O2- in that compartment . Most of the paraquat reduced in the cell, under the conditions used, reoxidized in situ and most of the O2- production was thus intracellular . The partitioning of reduced paraquat between intracellular and extracellular compartments, prior to reaction with dioxygen, depended upon intracellular pO2 and any strategy which raised intracellular pO2 decreased the efflux of reduced paraquat and thus decreased extracellular O2- production . Extracellular O2- and H2O2 did contribute to cell damage in proportion to the amount produced . O2- appeared to be unable to cross the cell envelope in either direction and the only O2- which was effective in raising the rate of biosynthesis of the manganese-superoxide dismutase, was that generated within the cell. J Biol Chem, 1979 Nov 10, 254(21), 10575 - 8 Site of action of RNase I on the 50 S ribosome of Escherichia coli and the association of the enzyme with the partially degraded subunit; Raziuddin et al.; The 50 S ribosome of Escherichia coli is partially degraded by RNase I in presence of a high concentration of Mg2+ (10 to 20 mM); the partially degraded subunit becomes resistant to the further action of RNase I . The latter remains latent in association with the subparticle as in case of 30 S ribosome (Neu, H.C., and Heppel, L.A . (1954) Proc . Natl . Acad . Sci . U.S.A . 51, 1267-1274) . As a result of nucleolytic action, 23 S RNA is degraded to a smaller size and four proteins (L4, L10, L7/L12) are released from the subunit . From the location of these proteins, it appears that the primary site of action of RNase I is the central protuberance of the armchair model proposed for the subunit (Stoffler, G., and Whitman, H.G . (1977) in Molecular Mechanisms of Protein Biosynthesis (Weissbach, H., and Pestka, S., eds) pp . 117-144, Academic Press, New York). Biochim Biophys Acta, 1979 Nov 9, 571(1), 55 - 62 Dephosphorylation of purine mononucleotides by alkaline phosphatases . Substrate specificity and inhibition patterns; Jensen MH; Three purine mononucleotides, adenosine-, inosine- and guanosine monophosphate, were used as substrates at pH 7.4 and at 10.4 for three alkaline phosphatases (orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.1) containing similar phosphate-binding serine groups at their esteratic sites . Substrate specificity was found for the enzymes from calf intestine and bovine liver . Alkaline phosphatase from Escherichia coli was nonspecific . A substrate-dependent and pronounced inhibition with the purine analogue 1,3-dimethyl xanthine was found for the enzymes from intestine and liver, but not for alkaline phosphatase from E . coli . A substrate-independent and pronounced inhibition was found for all three enzymes with the phosphomonoester p-nitrophenol phosphate as the inhibitor . Alkaline phosphatases may play an important role in the regulation of the intracellular content of purine mononucleotides. Sem Hop, 1979 Nov 8-15, 55(37-38), 1747 - 8 {Anterior perinephritic phlegmon (author's transl)}; Loup J; A case is reported of an unsuspected anterior perinephritic phlegmon which had caused peritonitis of pyelonephritic origin thought to be due to a cholecystitis . The lesion was discovered during laparotomy and intravenous urography at operation demonstrated the condition of the underlying kidney and determined the therapeutic approach and the prognosis. Biochem J, 1979 Nov 1, 183(2), 247 - 54 Wheat-germ aspartate transcarbamoylase . Steady-state kinetics and stereochemistry of the binding site for L-aspartate; Grayson JE et al.; 1 . The steady-state kinetics of the bisubstrate reaction catalysed by aspartate transcarbamoylase purified from wheat (Triticum vulgare)-germ have been studied at 25 degrees C, pH 8.5 AND I 0.10-0.12 . Initial-velocity and product-inhibition results are consistent with an ordered sequential mechanism in which carbamoyl phosphate is the first substrate to bind, followed by L-aspartate, and carbamoyl aspartate is the first product to leave, followed by Pi . The order of substrate addition is supported by dead-end inhibition studies using pyrophosphate and maleate as inhibitory analogues of the substrates . Product inhibition permitted a minimum value for the dissociation constant of L-aspartate from the ternary complex to be estimated . This minimum is of the same order as the dissociation constant (Ki) of succinate . 2 . A range of dicarboxy analogues of L-aspartate were tested as possible inhibitors of the enzyme . These studies suggested that L-aspartate is bound with its carboxy groups in the eclipsed configuration, and that the stereochemical constraints around the binding site are very similar to those reported for the catalytic subunit of the enzyme from Escherichia coli {Davies, Vanaman & Stark (1970) J . Biol . Chem . 245, 1175-1179}. Cell, 1979 Nov, 18(3), 843 - 53 Nonallelic histone gene clusters of individual sea urchins (Lytechinus pictus): polarity and gene organization; Cohn RH et al.; We have analyzed the histone genes from the sea urchin Lytechinus pictus . Examination of native DNA from individuals reveals four major Eco RI restriction endonuclease histone gene DNA fragments which have been labeled A (6.0 kb), B (4.1 kb), C (3.1kb) and D (1.2 kb) . The fragments A, B and C have been cloned into E . coli plasmids (pLpA, pLpB and pLpC) . These histone gene fragments display length and sequence heterogeneity in different individuals . The plasmid pLpA contains the coding regions for H1, H4, H2B and H3 histones, and we determined that the DNA fragment D is tandem to A in native DNA and that it contains the H2A gene . The plasmids pLpB and pLpC contain the histone genes H2A-H1-H4 and H2B-H3, respectively, and together contain the sequences for the five major histones . Restriction analysis of native L . pictus DNA reveals that B and C are tandem to each other but not intermingled with the A--D-type repeat units, and are thus in separate clusters with a repeat length of 7.2 kb . Since the two cluster types do not segregate, they are not alleles . Hybridization of histone mRNA to exonuclease III-digested linear DNA demonstrated an identical polarity of the histone genes in the A--D- and B--C-type repeat units . This result revealed that the L . pictus histone genes have a polarity which is the same as other sea urchin histone genes examined to date--that is, 3' H1-H4-H2B-H3-H2A 5' . Restriction endonuclease cleavage patterns of the cloned segments indicate that considerable sequence heterogeneity exists between the two types of histone gene repeat units. J Mol Evol, 1979 Nov, 13(4), 271 - 9 Post-maturation of the plastid ribosomal RNA in the plant kingdom; Rozier C et al.; The in vivo fragmentation of the plastid rRNA from plants situated at different places in the evolutionary sclae, with the exception of Algae, was analysed by electrophoresis using fully denaturing conditions . This fragmentation corresponds to an in vivo post-maturation . It exists only in some bacteria and is not random . Five main groups of fragments with the following real molecular weights (Mr) are found in 23 S: ca 0.9 x 10(6); 0.7 x 10(6); 0.45 x 10(6); 0.35 x 10(6) and 0.15 x 10(6) . The existence of a large fragment (Mr = 0.9 x 10(6)) corresponds to a primitive type of fragmentation found in some archaic plants . Dicotyledons and several other groups have the same pattern of 23 S fragmentation, often comprising all the fragments mentioned above, whilst Graminaceae (Monocotyledons) constitute a special group with a very predominant 0.35 x 10(6) dalton fragment and the absence of the 0.45 x 10(6) dalton fragment . The plastid 16 S rRNA in all plants studied here has a Mr of 0.54 x 10(6) which is smaller than the 16 S of Escherichia coli taken as reference (0.56 x 10(6) dalton). Tsitol Genet, 1979 Nov-Dec, 13(6), 492 - 6 {Use of mathematical recombination models for mapping Escherichia coli K-12 markers}; Dromashko SE et al.; The possibility is discussed of mapping the E . coli K-12 markers on the basis of mathematical models of recombination previously developed by the authors . The analysis showed that it is advisable to use the symmetrical crossing-over model for mapping the genes close to the selective marker . The stochastic model of recombination gives good results also for genes located in the proximal part of the chromosome. Mol Biol (Mosk), 1979 Nov-Dec, 13(6), 1384 - 96 {Quaternary structure of the ribosomal 30S subparticle: the model and its experimental verification}; Spirin AS et al.; In considering the structure of the ribosomal 30S subparticle from Escherichia coli we have assumed that : 1) all or almost all the proteins in the 30S subparticle are compact and globular as has been shown for isolated proteins S4, S7, S8, S15 and S16 in solution {Serdyuk I . N., Zaccai G . and Spirin A . S . (1978) FEBS Letters, 94, 349-352}; 2) RNA within the 30S subparticle has the same specific V-like or Y-like shape demonstrated for the isolated 16S RNA in a compact conformation {Vasiliev V . D., Selivanova O . M . and Koteliansky V . E . (1978) FEBS Letters, 95, 273-276} . On the basis of this assumption and numerous data published on the mutual localization of ribosomal proteins, we have constructed a model of the quaternary structure of the ribosomal 30S subparticle . We have tested the model by comparing the theoretically calculated curves of neutron and X-ray scattering at different contrasts with the corresponding experimental scattering curves of the E . coli 30S subparticles and have found that they coincide . The calculated scattering curves of several previously published three-dimensional diagrams of protein topography in the 30S subparticle do not agree with experiment. Mol Biol (Mosk), 1979 Nov-Dec, 13(6), 1327 - 40 {Cold-sensitive mutation in the beta-subunit of Escherichia coli RNA polymerase affecting the opening of promoters}; Larionov OA et al.; A cold-sensitive mutation in Escherichia coli, affecting the beta-subunit of RNA polymerase and causing an increase in the temperature of promoter opening on T2 phage DNA, was obtained . The mutation also affects the stages preceding promoter opening by increasing the dissociation rate of RNA polymerase--DNA closed complexes . The affinity of RNA polymerase to T2- and lambda-DNA is differently changed by the mutation . The relative efficiency of transcription of these two templates is also changed . These results suggest a participation of the beta-subunit of RNA polymerase in the interaction with promoters. Infect Immun, 1979 Nov, 26(2), 408 - 14 Prostaglandin regulation of colony-stimulating factor production by lipopolysaccharide-stimulated murine leukocytes; Moore RN et al.; The production of colony-stimulating factor by lipopolysaccharide-stimulated murine peritoneal leukocytes and their adherent subpopulations (greater than 80% macrophages) was markedly enhanced by indomethacin at concentrations sufficient to block prostaglandin E synthesis . Addition of physiological concentrations of E-series prostaglandins reversed this enhancing effect of indomethacin in a dose-dependent manner . These results indicate that colony-stimulating factor production by stimulated leukocytes is regulated by E-series prostaglandins and suggest that prostaglandins function to limit myelopoiesis by inhibiting colony-stimulating factor production and concomitantly the induction of cell proliferation. Appl Environ Microbiol, 1979 Nov, 38(5), 956 - 64 Plasmids in Escherichia coli controlling citrate-utilizing ability; Ishiguro N et al.; The citrate-utilizing ability of 19 out of 22 citrate-positive Escherichia coli strains isolated from pig sewage was transferred via conjugation to E . coli K-12 . The conjugal transfer of citrate-utilizing (Cit) abilities was thermosensitive and concurrent with transfer of drug resistance . Weakly citrate-positive colonies were readily obtained in conjugation experiments . Their Cit characters could be transmitted to the other E . coli strains at a similar frequency in the retransfer experiments, and the transconjugants obtained still showed same characteristic growth on Simmons citrate agar plates . The 19 thermosensitive plasmids conferring citrate utilization and drug resistance were Fi-, and 16 of these plasmids belonged to incompatibility group H1 . However, occasionally two conjugative plasmids (pOH3122-1 and pOH3124-1) carrying only the citrate utilization were also obtained in the conjugation experiments, and they were Fi+ and compatible with 19 reference R plasmids . In the two citrate-positive E . coli strains, it was suggested that the conjugative Cit plasmid showing Fi+ character and the more thermosensitive H1 plasmid conferring both the Cit character and drug resistance coexisted in the strain . The characterization of citrate utilization plasmids derived from pig farm sewage is discussed. Appl Environ Microbiol, 1979 Nov, 38(5), 911 - 5 Statistical procedure for evaluating the sensitivity of Limulus amoebocyte lysate by using a reference lysate; Rastogi SC et al.; A study was designed to estimate variability of the Limulus amoebocyte lysate test by comparing a reference lysate against itself . Three technicians performed parallel tests, i.e., titrated side by side, the contents of two vials of reference lysate on 4 different days using 24 vials of the United States reference lysate and 12 vials of the United States reference endotoxin . Each parallel test was replicated three times . From the sensitivity endpoints, ratios were calculated for each parallel test . These ratios were converted to the logarithm for estimating variability among technicians and among vials of endotoxin . By using the overall variability of log ratios, a statistical procedure was developed to evaluate the sensitivity of each lot of licensed lysate submitted to the Bureau of Biologics for release. Can J Biochem, 1979 Nov, 57(11), 1328 - 30 Hybrid plasmids complement a putP mutation in Escherichia coli K12; Wood JM et al.; Clarke and Carbon have prepared a colony bank of 2000 Escherichia coli strains each containing a random segment of the Escherichia coli chromosome inserted into the EcoR1 restriction site of the plasmid ColE1 . We have screened the colony bank by conjugation and have identified three strains bearing hybrid plasmids that complement a defective putP gene . Each of these strains shows increased L-proline uptake activity in comparison with the unmodified host or with the host bearing noncomplementing hybrid plasmids . However, CS520, the DNA source strain employed in constructing the hybrid plasmids, is a putP mutant . Since Escherichia coli possesses two L-proline porters, a variety of possible complementation mechanisms are discussed. J Gen Microbiol, 1979 Nov, 115(1), 89 - 94 Interrelation of DNA replication, specific growth rate and growth temperature in the sensitivity of Escherichia coli to cold shock; Gilbert P et al.; Escherichia coli W3110 was grown in a chemostat under conditions of carbon limitation at various temperatures and specific growth rates (mu) . Exponential survivor-time curves following cold osmotic shock were biphasic . These could be described by the sum of two exponential functions representing the survival of sensitive and resistant fractions of the population where the size of the sensitive fraction was directly proportional to mu . Decimal reduction times for the more resistant fraction were unaffected by mu yet decreased with increasing growth temperature . Sensitivity to cold shock was evaluated for an E . coli CR34 mutant, temperature-sensitive in initiation of DNA replication . When grown in the chemostat at the non-restrictive temperature (30 degrees C) sensitivity was directly proportional to mu . Following a rise in the incubation temperature to 42 degrees C, sensitivity decreased markedly and reached a minimum 45 to 60 min after the temperature increase . Sensitivity of the E . coli mutant grown at 30 degrees C and raised to 42 degrees C for 1 h was low and relatively unaffected by growth rate. J Gen Microbiol, 1979 Nov, 115(1), 69 - 77 Generation time statistics of Escherichia coli B measured by synchronous culture techniques; Plank LD et al.; Synchronous cultures of Escherichia coli B were produced under various environmental conditions . Analysis of the cell number data permitted the characterization of the generation time distribution for these organisms and the estimation of the mother-daughter generation time correlation coefficients . For all growth conditions, the distribution of generation times was found to be symmetrical with a coefficienoefficient was significantly negative at doubling times between 40 and 64 min . However, the results for a culture growing in succinate medium at 37 degrees C, which had a significantly greater generation time, yielded a correlation coefficient close to zero . Within the range of temperatures studied (26 to 37 degrees C), no significant effect on the correlation coefficient was observed. Biochem J, 1979 Nov 1, 183(2), 255 - 68 Impairment of the catalytic activity of Escherichia coli ribonucleic acid polymerase by a unique reaction of 4-chloro-7-nitrobenzofurazan; Bratcher SC et al.; Escherichia coli RNA polymerase loses 55-65% of its catalytic activity on reaction with Nbf-Cl (4-choro-7-nitrobenzofurazan) . This partial inactivation was shown to be the result of specific impairment of RNA-chain elongation, since initiation of RNA chains was not altered after treatment with Nbf-Cl . The site of reaction was shown to be a unique thiol on the beta-subunit . This thiol is not accessible to reaction with 5,5'-dithiobis-(2-nitrobenzoic acid) . No protection of the enzyme against reaction with Nbf-Cl could be obtained with the inhibitor rifamycin nor with calf thymus DNA, GTP or 1,10-phenanthroline, indicating that the unique thiol is probably not within the active site . The specific impairment of RNA-chain elongation thus appears to be the result of a local conformational change which leaves chain initiation unimpaired . Changes observed in the tryptophan fluorescence spectrum of the enzyme or reaction with Nbf-Cl are consistent with formation of a Meisenheimer complex of the reagent with a nucleophilic group on the enzyme near the reactive thiol . It is proposed that formation of such a complex and a subsequent conformational change renders this thiol unusually susceptible to reaction with Nbf-Cl. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5631 - 5 Detection of proteins like human gamma and beta globins in Escherichia coli carrying recombinant DNA plasmids; Wilson LB et al.; Escherichia coli strain chi 1776 carrying recombinant DNA plasmids containing cDNA copies of human beta or gamma globin mRNAs has been shown by radioimmunoassay to synthesize polypeptides antigenically related to the beta and gamma chains of human hemoglobin . The gamma and beta polypeptides have been enriched from lysates on immunoabsorbent columns containing hemoglobin antibodies and shown to specifically inhibit the antigen-antibody binding between 125I-labeled hemoglobin and the homologous antibody but not other hemoglobin-antihemoglobin reactions . Clone JW151, which is known to contain a complete copy of the coding portion of the gamma globin mRNA, has been shown to produce a protein that reacts specifically with antibody to the chain of fetal hemoglobin, hemoglobin Kenya, and hemoglobin Bart's. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5592 - 5 Biotinyl 5'-adenylate: corepressor role in the regulation of the biotin genes of Escherichia coli K-12; Prakash O et al.; A DNA filter-binding technique was used to study the interaction of the biotin repressor and operator site . From a biotin saturation curve, the concentration for half-maximal binding (K0.5) was calculated to be 1 microM . However, in a similar study with the in vitro coupled transcription-translation system in which biotin served as the corepressor, the K0.5 for repression was 7.1 nM . This marked difference of over 2 orders of magnitude was attributed to the activation of biotin by the partially purified repressor preparation in the in vitro system . The activated product formed from biotin, ATP, and repressor preparation was identified as biotinyl 5'-adenylate by paper chromatography and hydroxamic acid formation . Synthetic biotinyl 5'-adenylate was as effective as biotin in the in vitro system (K0.5, 10 nM) and much more effective than biotin in the DNA-binding assay (K0.5 1.1 nM versus 1 microM) . These studies indicate that biotinyl 5'-adenylate has a more direct role in the regulation of the biotin genes than does biotin per se. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5572 - 6 Replication at restrictive temperatures in Escherichia coli containing a polCts mutation; Niwa O et al.; Escherichia coli cells with a polCts mutation contain a temperature-sensitive DNA polymerase II and fall to replicate DNA at the restrictive temperature (43 degreees C) . Mutants deficient in polymerizing activity of the other two recognized DNA polymerases in E . coli can replicate DNA . We have isolated temperature-resistant revertants from a strain containing polA-, polB-, and polCts mutations . These revertants grow at 43 degrees C, but analysis of partially purified DNA polymerase III from several such revertants shows a temperature-sensitive DNA polymerase III activity . Genetic analysis by P1 transduction confirms that such revertants can contain a polCts mutation and also a polA- mutation . We find that such revertants behave phenotypically as PolI+ cells (DNA polymerase I-containing), and extracts of such cells show a DNA polymerase I-like activity . Revertants of polA-, dnaAts and polA-, dnaBts strains do not show such a DNA polymerase activity. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5544 - 8 Attractants and repellents control demethylation of methylated chemotaxis proteins in Escherichia coli; Toews ML et al.; A group of methylated proteins, the methyl-accepting chemotaxis proteins (MCP), has been shown to play a central role in bacterial chemotaxis . Both methylation and demethylation of MCP occur continuously in the absence of added stimuli; these two processes are in balance such that a basal level of methylation is maintained . Attractants cause the methylation level to increase to a new value, whereas repellents bring about a decrease in level . Therefore, attractants and repellents must somehow perturb the balance between methylation and demethylation of MCP . In this report the effect of attractants on demethylation of MCP was monitored in two ways: (i) by following the disappearance of {methyl-3H}MCP and (ii) by measuring formation of {3H}methanol, the product of MCP demethylation . Both methods showed that addition of attractants causes a transient inhibition of MCP demethylation . Repellent addition has previously been shown to stimulate MCP demethylation . It is therefore concluded that control of demethylation plays a crucial role in changing the level of methylation of MCP in response to attractants and repellents. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5529 - 33 Control of phosphoenolpyruvate-dependent phosphotransferase-mediated sugar transport in Escherichia coli by energization of the cell membrane; Reider E et al.; The phosphoenolpyruvate-dependent phosphotransferase-mediated sugar transport in Escherichia coli is inhibited by the energized of the membrane . This was shown in intact cells as well as in membrane vesicles . Relaxation of the proton gradient by uncouplers stimulated the uptake of sugars via the phosphotransferase system in aerobically cultured cells . No such effect was seen in anaerobic cells, apparently because the cell membrane of these cells is poorly energized . Energization by respiration of D-lactate or ascorbate inhibited the phosphotransferase uptake system in membrane vesicles . This inhibition was reversed by the addition of cyanide . Oxamate, a specific inhibitor of lactate dehydrogenase, prevented the inhibitory effect of D-lactate . Membrane vesicles prepared from a cytochrome-less mutant were not energized by D-lactate oxidation and the phosphotransferase uptake system was not inhibited. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5480 - 4 Initiation of Escherichia coli ribosomal RNA synthesis in vivo; Lund E et al.; The 5'-terminal sequences of Escherichia coli ribosomal RNA precursors (pre-rRNAs) synthesized in vivo were characterized by RNA oligonucleotide sequence analysis . The 60- to 170-nucleotide-long 5'-end-specific fragments were produced by RNase III treatment of 30S and 18S pre-rRNAs . Comparison of the RNA oligonucleotides of these fragments with known DNA sequences of the promoter regions of several ribosomal RNA operons allows us to determine the start points of transcription of each operon . We conclude that transcription of most (and perhaps all) rRNA operons is initiated in vivo at two tandem promoters, called P1 and P2, which have recently been identified by in vitro transcription studies of several groups . Depending on the transcription unit, the initiating nucleotide at P1 promoters is either ATP or GTP, whereas at P2 promoters it is either CTP or GTP. Mol Gen Genet, 1979 Nov, 176(3), 335 - 42 Stable yeast transformation with chimeric plasmids using a 2 micron-circular DNA-less strain as a recipient; Blanc H et al.; By using two chimeric plasmids containing yeast URA3 gene as a selection marker and 2 micron yeast DNA linked to the bacterial plasmid pCR1, a yeast strain devoid of any 2 micron DNA sequence was transformed . Recovery in E . coli of plasmids from yeast transformants showed that the 2 micron-less strain was able to maintain the chimeric plasmids as autonomous replicons, with very infrequent plasmid recombination . Hybridization experiments gave no evidence for integration of the URA3 DNA sequence in the chromosomal DNA . The transformed clones showed a high stability of the ura+ character during vegetative multiplication, even in the absence of selective pressure . The specific activity of orotidine 5' monophosphate decarboxylase (coded by the URA3 gene) was 5 to 10 fold higher than in the wild type . These features should offer new possibilities for cloning with yeast. Mol Gen Genet, 1979 Nov, 176(3), 313 - 8 The gene for ribosomal protein L25 (rplY) maps at 47.3 min near nalA in Escherichia coli K-12; Schnier J et al.; A temperature sensitive mutant, termed JE1306, derived from Escherichia coli strain PA3092 was found to have an alteration in the ribosomal protein L25 . Crosses with various Hfr strains and transductions with P1 kc phage have revealed that the mutation maps at 47.3 min between nalA and fpk, in a region where no ribosomal protein gene has so far been located . The gene affected by this mutation is most probably the structural gene for protein L25 (rplY), because a strain heteromerozygous for the region shows both wild type and mutant forms of protein L25. Immunology, 1979 Nov, 38(3), 503 - 8 The binding of LPS to the lymphocyte surface; Symons DB et al.; Bacterial lipopolysaccharide (LPS) from Escherichia coli labelled with tritium has been used to follow the binding of LPS to lymphocytes . Binding to cells rose to a maximum 2-7 min after addition of {3H}-LPS, followed by loss of {3H}-LPS from cells, reducing to about 10% of the peak level at 20-30 min . Peripheral blood lymphocytes, mesenteric lymph node and thymus cells of the pig and CBA, C3H/He and C3H/HeJ mouse spleen cells all bound {3H}-LPS transiently at similar levels . It is concluded that this type of LPS binding cannot be solely responsible for the preferential stimulation of B cells by LPS. Eur J Biochem, 1979 Nov, 101(2), 469 - 73 Interaction of arginine with the ribosomal peptidyl transferase centre; Palacian E et al.; Arginine inhibits the formation of acetylleucyl-puromycin from C(U)-A-C-C-A-LeuAc and puromycin ('fragment reaction'), catalized by Escherichia coli and yeast ribosomes . From 18 different L-amino acids assayed, arginine was the most effective in producing inhibition (50% inhibition at 20 mM, with 1 mM puromycin) . L-Argininamide and D-arginine gave about the same inhibition as L-arginine . The inhibition by L-arginine is competitive with respect to puromycin . The plot of the slopes obtained in a Lineweaver and Burk representation versus {Arg}2, and the plot of 1/v versus {Arg}2 at a fixed concentration of puromycin, are linear, which seems to indicate that two arginine molecules must interact at the puromycin binding site to produce inhibition . In addition to the 'fragment reaction', arginine inhibits the non-enzymatic binding of AcPhe-tRNA, C(U)-A-C-C-A-Leu and C(U)-A-C-C-A-LeuAc to ribosomes . However, it does not inhibit poly(U)-directed polyphenylalanine synthesis or the reaction of puromycin with AcPhe-tRNA previously bound to the peptidyl site . The results agree with arginine binding to the acceptor site, and with a sequential mechanism for the 'fragment reaction', puromycin binding first. J Med Microbiol, 1979 Nov, 12(4), 487 - 96 The ability of cholestyramine resin and other adsorbents to bind Escherichia coli enterotoxins; Mullan NA et al.; Several adsorbent materials were evaluated for their ability to bind Escherichia coli enterotoxins . Cholestyramine, a strong anion-exchange resin, bound the heat-labile and the heat-stable types of enterotoxin and reduced significantly their effects in some animal models . However, its efficacy in the treatment of diarrhoeic piglets appeared to be adversely affected by the presence of milk in the alimentary tract. Genetika, 1979 Nov, 15(11), 1971 - 8 {Nature of the compatible inheritance of hybrid plasmid pAS8 and its deletion mutants with replicon ColE1}; Stepanov AI et al.; Hybrid plasmid pAS8, that consists of RP4 and ColE1 replicons, is incompatible with RP4 but co-exists with ColE1 replicon . The deletion mutants of pAS8, that replicates under the control of ColE1 replicon only, are incompatible with ColE1 derivatives, although the copy number of pAS8 and its deletion mutants in the cell is the same (1-3 per the chromosome) . Incompatibility effect of plasmids is expressed in a sharp decrease in transformant's yield during selection of incoming and resident plasmids markers . In this case incompatibility is a very fast process, that leads to the elimination of resident or incoming plasmid just before plating on the selective medium . On the base of negative control theory, the repressors yield, synthesized in the presence of 1-3 copies of the deletion mutant is enough for the expression of ColE1-specific incompatibility . This ColE1 incompatibility is probably connected with the functional activity of ColE1 replicon . When ColE1 factor replicates under the control of RP4 replicon the expression of ColE1-specific incompatibility does not occur . Possibly, the incompatibility effect takes place when pAS8 deletion mutants cause the synthesis of ColE1-specific repressor . Also, the replicons of ColE1 may competein the membrane attachment site. Genetika, 1979 Nov, 15(11), 1918 - 24 {Chloroplast DNA cloning in Escherichia coli . II . The properties of the recombinant plasmids bearing the EcoRI fragments of pea chloroplast DNA and the cloning of the DNA sequences with rRNA genes}; Andrianov VM et al.; Previously a method of selection of colicine-defective recombinant plasmids by mitomycin C was described . A series of recombinant plasmids (CPS) with various EcoRI-fragments of pea chloroplast DNA has been obtained . This paper describes some properties of cloned fragments replicated in Escherichia coli . The alkali stability of recombinant plasmid DNAs has been demonstrated, indicating the absence of ribonucleotides in their structure . Heterogeneity of chloroplast DNA in nucleotide composition was demonstrated using ultracentrifugation analysis of CPS-plasmid DNAs in CsCl-actinomycin D density gradient . Pea chloroplast rDNA was cloned in recombinant plasmids. Eur J Biochem, 1979 Nov 1, 101(1), 123 - 33 Translation by Escherichia coli ribosomes of alfalfa mosaic virus RNA 4 can be initiated at two sites on the monocistronic message; Castel A et al.; Substantial evidence is provided to corroborate our previous finding that Escherichia coli ribosomes recognize two binding sites on the 5' end of alfalfa mosaic virus (AMV) RNA 4 {for a preliminary report see Castel, A., Kraal, B., Kerklaan, P . R . M., Klok, J., and Bosch, L . (1977) Proc . Natl Acad . Sci . U.S.A . 74, 5509--5513} . Translation can start at either site using AcPhe-tRNA or fMet-RNA as initiator and takes place in the same reading frame along the monocistronic mRNA . The size and composition of the isolated extra NH2-terminal fragment of the acetylphenylalanyl product were found to be in agreement with the 5' non-coding region of the messenger . Removal of the 5'-terminal cap structure of AMV RNA 4 did not influence significantly both initiation reactions . Ribosomal protein S1 was essential for binding as well as incorporation of both fMet-tRNA and AcPhe-tRNA . A similar interaction on the ribosome was found for AcPhe-tRNA directed by AMV RNA 4 as for fMet-tRNA directed by either AMV RNA 4 or MS2 RNA with respect to the influence of initiation factors . It is concluded that the heterologous plant viral messenger is reliably translated in the E . coli system and that E . coli ribosomes recognize with high specificity an extra initiation site close to the 5' extremity of the messenger . The relationship of this site to a hypothetical entry site involved in the early recognition in the initiation mechanism between ribosome and messenger is discussed. J Neurosurg, 1979 Nov, 51(5), 685 - 90 Production of experimental brain abscess in the rat; Winn HR et al.; Experimental evaluation of brain abscess has been inhibited by the lack of a simple and reproducible model in small animals . A stereotaxic headholder and slow infusion of 1 microliter of saline, containing a known number of bacteria, were used to produce brain abscess consistently in the rat . The natural history of the brain abscess produced by this technique closely simulated that found in the human clinical situation. J Bacteriol, 1979 Nov, 140(2), 620 - 33 Regulated breakdown of Escherichia coli deoxyribonucleic acid during intraperiplasmic growth of Bdellovibrio bacteriovorus 109J; Rosson RA et al.; During growth of Bdellovibrio bacteriovorus on {2-14C}deoxythymidine-labeled Escherichia coli, approximately 30% of the radioactivity was released to the culture fluid as nucleoside monophosphates and free bases; the remainder was incorporated by the bdellovibrio . By 60 min after bdellovibrio attack, when only 10% of the E . coli deoxyribonucleic acid (DNA) had been solubilized, the substrate cell DNA was degraded to 5 X 10(5)-dalton fragments retained within the bdelloplast . Kinetic studies showed these fragments were formed as the result of sequential accumulation of single- and then double-strand cuts . DNA fragments between 2 X 10(3) and 5 X 10(5) daltons were never observed . Chloramphenicol, added at various times after initiation of bdellovibrio intraperiplasmic growth on normal or on heated E . coli, which have inactivated deoxyribonucleases, inhibited further breakdown and solubilization of substrate cell DNA . Analysis of these intraperiplasmic culture deoxyribonuclease activities showed that bdellovibrio deoxyribonucleases are synthesized while E . coli nucleases are inactivated . It is concluded that continuous and sequential synthesis of bdellovibrio deoxyribonucleases of apparently differing specificities is necessary for complete breakdown and solubilization of substrate cell DNA, and that substrate cell deoxyribonucleases are not involved in any significant way in the degradation process. J Bacteriol, 1979 Nov, 140(2), 518 - 24 Alterations of deoxyribonucleoside triphosphate pools in Escherichia coli: effects on deoxyribonucleic acid replication and evidence for compartmentation; Pato ML; Inhibition of ribonucleic acid synthesis in Escherichia coli 15 TAU bar with rifampin or streptolydigin leads to large increases in the sizes of cellular ribonucleoside and deoxyribonucleoside triphosphate pools . Inhibition of protein synthesis leads to increases in the sizes of all nucleoside triphosphate pools except the guanosine triphosphate and deoxyguanosine triphosphate pools; a decrease in the size of the latter pool may be responsible for the slowing of deoxyribonucleic acid replication fork movement observed in this strain in the absence of protein synthesis . Analysis of the kinetics of incorporation of labeled precursors into deoxyribonucleic acid and into cellular pools suggests that functional compartmentation of nucleotide pools exists, allowing the incorporation of exogenously supplied precursors into deoxyribonucleic acid without prior equilibration with the cellular pools. J Bacteriol, 1979 Nov, 140(2), 445 - 51 Effect of blocking protein synthesis at nonpermissive temperatures on temperature-sensitive deoxyribonucleic acid mutants of Escherichia coli; Evans IM et al.; When protein synthesis was blocked in temperature-sensitive deoxyribonucleic acid synthesis mutants of Escherichia coli at nonpermissive temperatures, it reduced the amount of apparent subsequent chain elongation to approximately half that observed in the mutants either at nonpermissive temperatures alone or when protein synthesis was blocked at the permissive temperature . Blocking protein synthesis at the nonpermissive temperatures for periods of 40 min caused the loss of ability to reinitiate deoxyribonucleic acid synthesis at the permissive temperature. J Bacteriol, 1979 Nov, 140(2), 436 - 44 Multiple, independent components of ultraviolet radiation mutagenesis in Escherichia coli K-12 uvrB5; Smith KC et al.; Reversion systems involving the lacZ53(amber) and leuB19)missense) mutations were developed to study the mutant frequency response of Escherichia coli K-12 uvrB5 (SR250) to ultraviolet radiation (254 nm) . A one-hit mutant frequency response was discernible at ultraviolet radiation fluences below approximately 0.5 J m-2 . At higher fluences the overall mutant frequency response could be resolved into one-hit and two-hit components . A new interpretation of the published data on E . coli K-12 indicates that SR250 is not unique in this respect . In addition, the Lac reversion system showed enhanced mutagenesis after ultraviolet radiation fluences of approximately 1 to 3 J m-2, whereas the Leu reversion system did not . We conclude that the complex ultraviolet radiation mutant frequency response curves for E . coli K-12 uvrB5 were the result of three independent mutagenic processes for Lac reversion and two for Leu reversion. J Bacteriol, 1979 Nov, 140(2), 388 - 94 Role of the ftsA gene product in control of Escherichia coli cell division; Donachie WD et al.; The kinetics of cell division have been studied in a strain of Escherichia coli which has an amber mutation in the ftsA gene and which also carries a temperature sensitive amber suppressor . This strain is therefore temperature sensitive for the synthesis of the ftsA protein . Cells of this strain were able to divide only if the synthesis of this protein took place during a specific part of the cell cycle . This was a short period (roughly 10 min in duration) immediately before the normal time of cell division. J Bacteriol, 1979 Nov, 140(2), 377 - 80 Microcalorimetric study of Escherichia coli aerobic growth: kinetics and experimental enthalpy associated with growth on succinic acid; Dermoun Z et al.; A new batch calorimeter was used to study the aerobic growth of Escherichia coli in a minimal containing a growth-limiting concentration of succinic acid . The shape of the thermograms obtained was simple when the energy source was the only growth-limiting factor and showed a stationary phase when the oxygen transfer was limiting . The experimentally determined value of the heat production during growth was found to be significantly lower than the heat of combustion of the succinic acid corrected for the assimilated-substrate fraction . An interpretation has been given to explain the difference between the experimental and the theoretical values. J Bacteriol, 1979 Nov, 140(2), 311 - 9 Inversion in the lactose region of Escherichia coli K-12; Savic DJ; A spontaneous mutant of Escherichia coli K-12, strain SY99, with an inversion in the lactose region was isolated and partially characterized . The inversion was detected due to inverse chromosomal conjugational transfer after introduction of an F42 (F'lac) episome . The termini of the inversion are between proAB and lac on one side and lac and proC on the other . The inverse conjugational transfer in SY99 did not appear to be absolute but was always accompanied by a residual "normal" counterclockwise mobilization . This residual transfer was further shown to be caused by the intrinsic instability of this region (at least in the line W3110) . The possible involvement of IS3 elements flanking the lactose operon is discussed. CRC Crit Rev Biochem, 1979 Nov, 7(1), 45 - 74 Analysis of in vitro replication of different DNAs; Hurwitz J; The conversion of single-stranded circular DNA to duplex DNA in vitro occurs by at least three different mechanisms . These differences reside in the manner of priming of these DNAs . In contrast, the elongation of primed DNA templates is a general reaction . A number of these proteins have been isolated and further characterized . In addition, cell-free preparations capable of supporting phi X RFI DNA replication as well as the synthesis of progeny viral phi X174 single-stranded circular DNA have been prepared. Cancer Res, 1979 Nov, 39(11), 4512 - 5 Correlation between metabolic reduction rates and electron affinity of nitroheterocycles; Olive PL; Nitroheterocyclic compounds can selectively sensitize hypoxic (tumor) cells to radiation damage in vitro . However, results in vivo have generally been less optimistic, inasmuch as metabolic reduction of these drugs not only limits effective lifetime but also produces metabolic intermediates with marked cytotoxic and carcinogenic activity . With three reducing systems in vitro, E . coli B/r, mouse L-929 cells, and mouse liver microsomes, the rate of nitroreduction of several nitroheterocycles was found to be proportional to their electron affinity (half-wave reduction potential) . Relative to the rate of nitrofurazone reduction in each system, metronidazole (Flagyl), N-hydroxyethyl-3,5-dinitropyrrole, misonidazole, nifuroxime, nitrofurantoin, and furylfuramide were metabolized about 200, 20, 2, 1.4, and 1.2 times less rapidly, while 3,5-dinitrobenzonitrile, 2,5-dinitrophenol, and 5-nitro-2-furaldehyde diacetate were reduced 2, 3, and 4 times more rapidly . Since nitroreduction has previously been correlated with subsequent cytotoxicity, DNA damage, and mutagenicity, the present results suggest that improvements in the therapeutic efficacy of nitroheterocycles (i.e., sensitization without toxicity and carcinogenicity) will be dependent on development of drugs with more appropriate pharmacological properties. Br J Haematol, 1979 Nov, 43(3), 457 - 63 Reduced leucocyte alkaline phosphatase activity and decreased NBT reduction test in induced iron deficiency anaemia in rabbits; Celada A et al.; Iron deficiency anaemia was induced in rabbits by repeated bleeding . The leucocyte alkaline phosphatase (LAP) of 26 +/- 28 units was significantly reduced compared with control values of 233 +/- 35 units (P less than 0.001) . Leucocyte NBT reduction was also diminished, both in Hanks solution (P less than 0.01) and in autologous serum (P less than 0.001) . After administration of iron, these values returned to normal . The results suggest that reduced LAP may reflect a deficiency of iron dependent constituents which are necessary for the integrity of normal granulocyte metabolism. Mol Biol (Mosk), 1979 Nov-Dec, 13(6), 1341 - 9 {Effect of DNA supercoiling on transcription performed by normal and mutant Escherichia coli RNA-polymerases}; Mirkin SM et al.; A specific DNA-gyrase, inhibitor, coumermycin A1, causes differential changes in the spectrum of proteins synthesized in E . coli wild types cells, while protein spectrum in the mutant cells with coumermycin-resistant DNA-gyrase is left unaffected . The mutation of RNA-polymerase RpoB265 lowers the sensitivity of bacteria to coumermycin A1, whereas the RpoC3 enhances it . The differences between the normal and mutant RpoB265 RNA polymerases on interaction in vitro with ColE1 DNA plasmid depend on its supercoiling . No dependences of this kind were detected when comparing the normal and RpoC3-RNA polymerase . The obtained data indicate that the template supercoiling may significantly affect the transcription in vivo and that the properties of RNA polymerase may in some cases define this influence. Can J Biochem, 1979 Nov, 57(11), 1281 - 3 In vivo preparation of {32P}cAMP and thin-layer chromatography of cAMP-related compounds; Yamazaki H et al.; A simple and rapid method for preparing {32P}adenosine 3'5'-cyclic monophosphate (cAMP) is described . A culture of an Escherichia coli mutant which excretes cAMP about 150 times faster than does a wild-type strain was incubated overnight with {32P}orthophosphate of high specific activity (e.g., 4000 Ci/mol (1 Ci = 37 GBq) . The {32P}cAMP which accumulated extracellularly was then purified to 99.9% radiochemical purity in less than 4 h by adsorption to charcoal and alumina column chromatography . A two-dimensional chromatography system using a PEI-cellulose plate is also described which should prove useful for studying cAMP metabolism with 32P- or 3H-labeled cAMP or ATP. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5596 - 600 Synthesis of simian virus 40 t antigen in Escherichia coli; Roberts TM et al.; Plasmids are constructed by using recombination in vitro according to Roberts, T.M., Kacich, R . & Ptashne, M . (1979) Proc . Natl . Acad . Sci . USA 76, 760-764 in which the t antigen gene of simian virus 40 is fused to a promoter of the Escherichia coli lac operon . In the fusions, transcription commences at the lac promoter, and, in some of the fusions, translation begins at the ATG initiator codon of the t gene . This translation is directed most efficiently by those plasmids in which the lac sequences abut the t gene such that a hybrid ribosome binding is encoded . In this case, the Shine-Dalgarno sequence is of lac origin but the ATG derives from the t gene . translation from this initiator codon is greatly decreased if the lac sequences are separated from the ATG by 17 base pairs and is abolished if the AT of this triplet is deleted . Cells bearing the productive fusions synthesize a 20,000-dalton protein with t antigenic determinants . This protein has an isoelectric point(s) indistinguishable from that of t antigen isolated from simian virus 40-transformed cells . Moreover, a partial sequence of the amino-terminal region of the bacterial product is that predicted for authentic t antigen . We conclude that these bacteria are for authentic t antigen . We conclude that these bacteria are producing a protein, the sequence of which is identical to that of authentic t antigen unfused to other polypeptides. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5567 - 71 Spliced adenovirus-associated virus RNA; Laughlin CA et al.; We describe the structure of cytoplasmic RNA species transcribed from the DNA of adenovirus-associated virus, a defective parvovirus . The RNA was hybridized with minus strand template DNA and visualized in the electron microscope . Alternatively, the DNA.RNA duplex molecules were digested with nuclease S1 or Escherichia coli exonuclease VII and analyzed by agarose gel electrophoresis . A set of RNA species was observed with 5' terminal at map positions 5, 13, 19, or 39 and a 3' terminus and poly(A) tail at position 96 (one map unit is equivalent to 1% of genome length) . Most of these RNAs are spliced and lack sequences approximately between positions 40 and 49 . Some RNA preparations also contained unspliced molecules with 5' and 3' terminal at positions similar to those in the spliced RNA. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5520 - 3 Regulation of synthesis of a major outer membrane protein: cyclic AMP represses Escherichia coli protein III synthesis; Mallick U et al.; Cyclic AMP is the effector molecule for both positive and negative control of synthesis of several Escherichia coli proteins . Among the latter is the major outer membrane protein III . The control mechanism occurs at the level of transcription and involves the cyclic AMP receptor protein . The repressing system is saturated at lower concentrations of cyclic AMP than is the positive control system. Mol Gen Genet, 1979 Nov, 176(3), 449 - 50 Control of minicell producing cell division by cAMP-receptor protein complex in Escherichia coli; Kumar S et al.; It has been established that the strain CA8000 of Escherichia coli K12 produces minicells . This phenotype of CA8000 has been shown to be suppressed by additional mutations in cya or crp genes . Minicell production by cya+ crp+ min bacteria is probably a consequence of error, introduced by horizontal growth, in the selection of site on the envelope for initiation of hemispherical growth. Mol Gen Genet, 1979 Nov, 176(3), 375 - 7 The stimulation of Escherichia coli stringent factor-dependent synthesis of guanosine 3',5'-polyphosphate {(p)ppGpp} by rat liver ribosomal proteins; Fehr S et al.; The effect of groups of proteins from rat liver ribosomes on the Escherichia coli stringent factor-catalyzed synthesis of (p)ppGpp was tested . Most groups were capable of supporting (p)ppGpp synthesis; the exceptions were A40, B140, B240 and B160 which contain proteins which are relatively less basic than those in the active groups . The capacity of 30 individual rat liver ribosomal proteins to activate stringent factor was assessed; most sustained the synthesis of (p)ppGpp . Proteins S12, S21, L12, P1, and P2 (which are acidic or relatively acid) had no activity; proteins S6, S8, and L3 were the most active: the others had moderate activity. Mol Gen Genet, 1979 Nov, 176(3), 343 - 50 Involvement of cyclic AMP and its receptor protein in the sensitivity of Escherichia coli K 12 toward serine: excretion of 2-ketobutyrate, a precursor of isoleucine; Daniel J et al.; A relationship between serine-induced growth sensitivity and the cAMP-CAP complex is established . Mutants of Escherichia coli K 12 deficient either in the cya or crp gene function exhibit a resistant phenotype on serine media although they harbor a relA allele normally leading to sensitivity toward serine . The presence of a crp allele in a cya delta relA background restores the sensitivity phenotype, while the analysis of serine resistant mutants selected from a crp cya delta relA strain shows that the mutation leading to resistance is located at, or very near, the crp gene, giving a more or less Crp- phenotype . In addition crp cya delta relA strains excrete large quantities of 2-ketobutyrate when grown on glucose M63 medium . This excretion is unambiguously linked to the presence of the crp allele and is correlated with an enhanced threonine deaminase activity . Besides, the complex regulation exerted on the acetolactate synthase activities is discussed. Gene, 1979 Nov, 7(3-4), 335 - 42 Construction and characterization of a recombinant plasmid encoding the gene for the thymidine kinase of Herpes simplex type 1 virus; Enquist LW et al.; We have constructed a hybrid plasmid by insertion of the thymidine kinase (TK) gene of Herpes simplex virus (HSV) type I at the BamHI site on Escherichia coli plasmid pBR322 . The restriction endonuclease cleavage site map for the viral DNA fragment was determined for ten nucleases, and the insert in the recombinant plasmid has the same restriction nuclease digestion pattern as bona fide viral DNA . This result indicates that the plasmid contains an accurate copy of the viral DNA . The viral TK gene carried on the plasmid can be introduced into mammalian cells where it is expressed . This source of DNA with a selectable marker should be of considerable practical use in gene-transfer experiments in mammalian cells. J Bacteriol, 1979 Nov, 140(2), 459 - 67 Transport of cyclic adenosine 3',5'-monophosphate across Escherichia coli vesicle membranes; Goldenbaum PE et al.; The uptake and efflux of cyclic adenosine 3',5'-monophosphate (3',5'-cAMP) by Escherichia coli membrane vesicles were studied . Metabolic energy was not required for the uptake process and was found to actually decrease the amount of 3',5'-cAMP found in the vesicles . 3',5'-cAMP uptake exhibits saturation kinetics (Km = 10 mM, Vmax = 2.8 nmol/mg of protein per min) and was competitively inhibited by a number of 3',5'-cAMP analogs . The uptake of 3',5'-cAMP was found to be sharply affected by a membrane phase transition . The excretion of 3',5'-cAMP was studied by using everted membrane vesicles . Efflux in this system was dependent upon metabolic energy and was reduced or abolished by uncouplers . Different energy sources powered efflux at different rates, showing a relationship between the degree of membrane energization and rate of excretion of 3',5'-cAMP . The efflux process also displayed saturation kinetics (Km = 10.0 mM, Vmax = 0.98 nmol/mg of protein per min) and was competitively inhibited by the same 3',5'-cAMP analogs and to the same degree as was the uptake process . 3',5'-cAMP was found to be chemically unaltered by both the uptake and excretion processes . These data are interpreted as showing that the uptake and excretion of 3',5'-cAMP in E . coli membrane vesicles are carrier-mediated phenomena, possibly employing the same carrier system . Uptake is by facilitated diffusion whereas efflux is via an energy-dependent, active transport process . Evidence is presented showing that cells can regulate the number of 3',5'-cAMP transport carriers . The rate of 3',5'-cAMP excretion is possibly regulated by both the degree of membrane energization and the number of carriers present per cells. J Bacteriol, 1979 Nov, 140(2), 415 - 23 Production and excretion of cloacin DF13 by Escherichia coli harboring plasmid CloDF13; Van Tiel-Menkvled GJ et al.; The production and the mechanism of excretion of cloacin DF13 were investigated in noninduced and mitomycin C-induced cell cultures . A mitomycin C concentration was selected which did not cause lysis of cloacinogenic cells, but at the same time induced a maximal production of cloacin DF13 . Native cloacin DF13, possessing killing activity, was first released into the cytoplasm . Shortly thereafter, the bacteriocin was transported through the cytoplasmic membrane and accumulated in the periplasm . Finally, cloacin DF13 was excreted into the culture medium . A small amount of cloacin DF13 remained associated with the cell surface . Producing cells did not become permeable for the cytoplasmic enzyme beta-galactosidase . Apparently the cloacin DF13 leaves the producing cells by an excretion process which is not similar to the mechanism proposed for bacterial secretory proteins . The processes of excretion by producing cells and of uptake by susceptible cells were also not identical because mutant cloacin DF13, which was not transported through the outer membrane into susceptible cells, was excreted like the wild-type cloacin DF13 . The composition of the culture medium greatly affected production of cloacin DF13 . The presence of sugars known to cause catabolite repression not only inhibited the production but also strongly reduced the excretion of cloacin DF13 into the culture medium. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5799 - 803 Gene expression of an Escherichia coli ribosomal RNA promoter fused to structural genes of the galactose operon; Ota Y et al.; The promoter region of the rrnB ribosomal RNA gene of Escherichia coli has been ligated within the epimerase gene (galE) of the galactose operon in a lambda phage vector . The recombinant lambda phage has been characterized by restriction mapping and assays of both galK (galactokinase) gene activity and galactose messenger RNA hybridization . In such lyosgens, expression of the fused galactose operon occurs as a function of growth rate in a manner characteristic of ribosomal RNA gene expression and is subject to stringent control by amino acid availability for protein synthesis . Galactose messenger RNA arising from the ribosomal promoter is not as metabolically stable as ribosomal RNA. Mol Gen Genet, 1979 Nov, 176(3), 361 - 8 Cloning the trpR gene; Roeder W et al.; In Escherichia coli, the structural gene for purine nucleoside phosphorylase, deoD, is subject to insertional inactivation by prophage lambda . From one such secondary site lambda lysogen, strain SP265, one may isolate deletions that remove all or part of the trpR gene and other genes in the deo-thr sector of the E . coli chromosome . Specialized transducing phages harboring serB+ and trpR+ were liberated following induction of SP265 . All such phages were N-defective, bio-type pseudolysogens whose DNA persisted in the form of plasmids . A collection of transducing phages, differing in their complement of bacterial DNA, was used to locate cleavage sites for BamHI, SalI, and PvuI within the deoD-trpR region of the E . coli genome . The trpR gene lies within a specific 950 base pair BamHI-PvuI segment . A 1250 base pair BamHI fragment carrying a functional trpR gene was cloned into the amplifiable plasmid pBR322 . A single SalI site in this fragment was shown to lie within the TrpR gene . In two situations where increased gene dosage might generate elevated amounts of Trp repressor (N-defective trpR+ pseudolysogens and strains harboring pBR322 trpR+ plasmids) neither tryptophan auxotrophy, enhanced sensitivity to DL-5-methyl-tryptophan, nor super repression of the tryptophan biosynthetic enzymes was observed. Gene, 1979 Nov, 7(3-4), 181 - 95 A rightward promoter to the left of the att site of lambda phage DNA: possible participant in site-specific recombination; Kravchenko VV et al.; The binding has been studied of Escherichia coli RNA-polymerase to the fragments of lambda DNA obtained by digestion with restriction endonucleases BsuI, HindIII, BamHI, EcoRI and HindII + III . There are at least six sites of RNA-polymerase binding in the b2-region . In vitro transcription of those BsuI-fragments of the b2-region which contain six binding sites is rightward . Therefore, the fragments contain promoters rather than mere RNA-polymerase binding sites . One of the promoters of the b2 region named patt was calculated to be about 50 bp to the left of the att site . We postulate that this promoter might correspond to the hef-target which was described as important for the site-specific recombination. J Bacteriol, 1979 Nov, 140(2), 381 - 7 Suppression of tif-mediated induction of SOS functions in Escherichia coli by an altered dnaB protein; D'Ari R et al.; The tif-1 mutation in the Escherichia coli recA gene is known to cause induction of the various "SOS" functions at high temperature, including massive synthesis of the recA protein, lethal filamentation, elevated mutagenesis, and, in lambda lysogens, induction of prophage . It is shown here that the deoxyribonucleic acid initiation mutation dnaB252 suppresses all these manifestations of tif expression . Induction of lambda by ultraviolet irradiation, however, is not affected by the dnaB252 mutation . No similar suppression of tif is observed with other dnaB mutations affecting deoxyribonucleic acid elongation or with other deoxyribonucleic acid initiation mutations at the dnaA and dnaC loci . The fact that an alteration of the dnaB protein specifically suppresses tif-mediated SOS induction implies a role of the replication apparatus in this process, as has been suggested for ultraviolet induction . The induction of lambda is known to proceed via repressor cleavage, presumably promoted by an activated (protease) form of the recA protein . Since lambda induction is normal after ultraviolet irradiation of the tif-1 dnaB252(lambda) strain, tif-mediated induction in this strain may be blocked in a tif-specific step leading to activation of the recA (tif) protein . It is possible that the recA (tif) mutant protein may be directly involved in the replication complex in processes leading to this activation. Proc Natl Acad Sci U S A, 1979 Nov, 76(11), 5524 - 8 Attenuation in the Escherichia coli tryptophan operon: role of RNA secondary structure involving the tryptophan codon region; Oxender DL et al.; The secondary structure of the terminated trp leader transcript from Escherichia coli was analyzed by RNase T1 partial digestion . Base-paired regions were recovered by nondenaturing gel electrophoresis and identified by denaturing gel electrophoresis and fingerprinting . The tandem tryptophan codons in the leader peptide coding region were found to be base paired with a more distal region of the transcript . This and other secondary structures that the trp leader RNA can form help explain the physiological response of the operon as well as the behavior of regulatory mutants. J Biochem (Tokyo), 1979 Nov, 86(5), 1233 - 8 In vivo methylation of elongation factor Tu of Escherichia coli; Ohba M et al.; A protein existing mainly in the supernatant fraction of Escherichia coli was found to be methylated by accepting the methyl moiety originating from methionine . The protein was identified as peptide synthesis elongation factor Tu (EF-Tu) by the following criteria . 1) The methylatable protein separated at the same position as purified EF-Tu on two-dimensional gel electrophoresis . 2) The methylatable protein interacted with antiserum specific for EF-Tu . Amino acid analysis of the methyl-labeled protein suggested that the site of methylation was an epsilon-amino group of lysine. Gene, 1979 Nov, 7(3-4), 197 - 215 Isolation and characterization of recombinant DNA plasmids carrying Drosophila tRNA genes; Dunn R et al.; Recombinant plasmids carrying Drosophila melanogaster tRNA genes were constructed by ligation of HindIII-cleaved Drosophila DNA to HindIII cut pBR322 DNA . 90 clones were isolated that contained genes for one or more of eleven tRNAs . 43 of the plasmids were characterized by a number of methods: restriction nuclease digestion; agarose gel electrophoresis; hybridization with individual, purified, 125I-labelled Drosophila tRNA molecules and in situ hybridization to Drosophila chromosomes . The results show that several different tRNA genes have been isolated which code for single, specific isoacceptors . The DNAs from 8 plasmids each hybridize to single sites on Drosophila polytene chromosomes . In addition, the data show examples of two different plasmids hybridizing to different loci coding for the same tRNA; this means that we have isolated representatives of tRNA genes which map at widely separated points on the Drosophila genome. Genetika, 1979 Nov, 15(11), 1925 - 36 {Mutations in the purine nucleoside phosphorylase (pup) gene of Escherichia coli K-12 characterized by leaky damage to enzymatic activity and a pleiotropic effect}; Skladnev DA et al.; The phenotype of earlier obtained mutants AIR38 and AIR6 is caused by leaky mutations of the structural gene for purine nucleoside phosphorylase (pup) . These mutants are unable to grow on the medium with inosine as the only carbon source in the presence of thymidine . In contrast to ordinary leaky mutations, AIR38 and AIR6 are dominant in heterozygotes . When the strain F' with mutations AIR38 or AIR6 on episomes was used for conjugational matings with F- recA (pup+), recombinants with unexpected phenotype were observed: about 20% of recombinants F' became pup+ and thus the convertion of AIR38 and AIR6 alleles to pup+ took place . AIR38 mutation, unlike AIR6, is mapped in the proximal region of the pup gene and is characterized by pleyotropic effect on deo-genes: the inosine-induction of purine nucleoside phosphorylase in AIR38 mutant is absent and the induction of thymidine phosphorylase by exogenous thymidine is decreased . A speculation was made that the mutation AIR38 altered the structure of purine nucleoside phosphorylase in the site responsible for its interaction with membrane. J Bacteriol, 1979 Nov, 140(2), 342 - 50 Transcriptional regulation of Escherichia coli K-12 major outer membrane protein 1b; Hall MN et al.; Eleven independent insertion mutations were isolated that prevented expression of major outer membrane protein 1b . Seven of the mutations were Mucts insertions located at ombP . These ompB::Mucts strains fell into two phenotypic classes with regard to expression of proteins 1a and 1b . The remaining four mutants were comprised of one Tn5 and three Mucts insertions mapping at par . The Mucts insertions at par were used to construct fusions of the lac operon to the par promoter . Expression of beta-galactosidase in these fusion strains reflected known regulatory properties of protein 1b . When an ompB allele was introduced into the par-lac fusion strains, beta-galactosidase activity was reduced 14- to 31-fold . Transcriptional regulation of the par gene and the existence of two functions at ompB are discussed . The results suggest that par is the structural gene for protein 1b and that an ompB gene product is a diffusible, positive regulatory element controlling expression of par. Mol Biol (Mosk), 1979 Nov-Dec, 13(6), 1413 - 9 {Inhibition of RNA synthesis in vitro by antibodies against mononucleotides}; Makarova OV et al.; Antibodies against purine nucleotides were obtained from rabbits immunized with conjugates of bovine serum albumine with AMP or GMP . The antibodies purified by affinity chromatography on nucleoside monophosphate-human serum albumine-Sepharose columns inhibited RNA synthesis on native T4 phage DNA by E . coli RNA polymerase . The inhibition of transcription was due mainly to inhibition of the initiation stage of RNA synthesis. J Antibiot (Tokyo), 1979 Nov, 32(11), 1181 - 5 Response to bleomycin of Escherichia coli mutants deficient in DNA repair; Yamamoto K et al.; The effect of bleomycin on the colony forming ability of Escherichia coli K12 strains in exponential growth at 37 degrees C was not affected by introducing recA13, lexA1, polA1 and uvrA6 mutations . For cells starved for amino acids, wild type strains became ten-fold more resistant to bleomycin, but again introducing lexA1, polA1 and uvrA6 strains did not change the effect on colony forming ability; however, starved recA13 cells were now four-fold more sensitive . Strains with recA13, lexA1 and polA1 mutations were always more sensitive than wild type to gamma rays under the same conditions as used for the bleomycin treatment . It is suggested that bleomycin-induced lesions may be concentrated in that part of the bacterial genomes at the cell wall, near the replication forks. Infect Immun, 1979 Nov, 26(2), 453 - 7 In vitro adherence of radioactively labeled Escherichia coli in normal and cystitis-prone females; Parsons CL et al.; Numerous investigators report data obtained using an in vitro quantitative assay for measuring bacterial adherence to epithelial cells . We found this assay to contain significant sources of error in the large variation in number of bacteria bound per cell and in the dependence on the investigator's visual counting of bacteria bound per cell . In the modified assay described here, we eliminated the need for visual counting of bacteria by incorporating the use of radioactively labeled Escherichia coli . This allowed quantitation of bacterial adherence to as many as 50,000 vaginal cells, whereas the visual counting system limits the determination to perhaps 50 cells . We feel that the use of radioactively labeled bacteria in place of the visual counting system increases the validity and sensitivity of this assay . Using the modified method, we found no statistically significant differences among values for adherence of E . coli type 04 to the vaginal cells of control and cystitis-prone women at either pH 6.4 or 4.0. J Biochem (Tokyo), 1979 Nov, 86(5), 1251 - 7 Phosphoenolpyruvate carboxylase of Escherichia coli . Affinity labeling with bromopyruvate; Kameshita I et al.; Phosphoenolpyruvate carboxylase {EC 4.1.1.31} from Escherichia coli W was alkylated by incubation with bromopyruvate, substrate analog, leading to irreversible inactivation . The reaction followed pseudo-first-order kinetics . Mg2+, an essential cofactor for catalysis, enhanced the inactivation, and the enhancing effect increased as the pH increased . The inactivation rate showed a tendency to saturate with increasing concentrations of bromopyruvate, indicating that an enzyme-bromopyruvate complex was formed prior to the alkylation . DL-Phospholactate, a potent competitive inhibitor with respect to phosphoenolpyruvate, protected the enzyme from inactivation in a competitive manner . Examination of the acid hydrolysate of the enzyme modified with {14C}bromopyruvate by paper chromatography showed that radioactivity was solely incorporated into carboxyhydroxyethyl cysteine . In addition, determination of sulfhydryl groups of the native and modified enzymes with 5,5'-dithiobis(2-nitrobenzoate) showed that inactivation occurred concomitant with the modification of one cysteinyl residue per subunit . The results indicate that bromopyruvate reacted with the enzyme as an active-site-directed reagent. J Biochem (Tokyo), 1979 Nov, 86(5), 1239 - 49 Studies on regulatory functions of malic enzymes . VII . Structural and functional characteristics of sulfhydryl groups in NADP-linked malic enzyme from Escherichia coli W; Iwakura M et al.; NADP-linked malic enzyme from Escherichia coli W contains 7 cysteinyl residues per enzyme subunit . The reactivity of sulfhydryl (SH) groups of the enzyme was examined using several SH reagents, including 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and N-ethylmaleimide (NEM) . 1 . Two SH groups in the native enzyme subunit reacted with DTNB (or NEM) with different reaction rates, accompanied by a complete loss of the enzyme activity . The second-order modification rate constant of the "fast SH group" with DTNB coincided with the second-order inactivation rate constant of the enzyme by the reagent, suggesting that modification of the "fast SH group" is responsible for the inactivation . When the enzyme was denatured in 4 M guanidine HCl, all the SH groups reacted with the two reagents . 2 . Althoug the inactivation rate constant was increased by the addition of Mg2+, an essential cofactor in the enzyme reaction, the modification rate constant of the "fast SH group" was unaffected . The relationship between the number of SH groups modified with DTNB or NEM and the residual enzyme activity in the absence of Mg2+ was linear, whereas that in the presence of Mg2+ was concave-upwards . These results suggest that the Mg2+-dependent increase in the inactivation rate constant is not the result of an increase in the rate constant of the "fast FH group" modification . 3 . The absorption spectrum of the enzyme in the ultraviolet region was changed by addition of Mg2+ . The dissociation constant of the Mg2+-enzyme complex obtained from the Mg2+- dependent increment of the difference absorption coincided with that obtained from the Mg2+- dependent enhancement of NEM inactivation . 4 . Both the inactivation rate constant and the modification rate constant of the "fast SH group" were decreased by the addition of NADP+ . The protective effect of NADP+ was increased by the addition of Mg2+ . Based on the above results, the effects of Mg2+ on the SH-group modification are discussed from the viewpoint of conformational alteration of the enzyme. Genetika, 1979 Nov, 15(11), 1963 - 70 {Effect of plasmid F'Col+trp+ on the transfer of plasmid RP4}; Gol'dfarb DM et al.; Interaction of conjugative plasmids F'colV colB trp and PR4 in Escherichia coli host was studied during the transfer of the plasmids from cell to cell . The plasmid F'colV colB trp is found to stimulate the transfer of RP4 from the diplasmid strain . This seems to be due to stabilization of the conjugating pairs which require normal pili coded by the plasmid F'colV colB trp. J Bacteriol, 1979 Nov, 140(2), 395 - 9 Sucrose transport by the Escherichia coli lactose carrier; Heller KB et al.; Several lines of evidence suggest that sucrose is transported by the lactose carrier of Escherichia coli . Entry of sucrose was monitored by an osmotic method which involves exposure of cells to a hyperosmotic solution of disaccharide (250 mM) . Such cells shrink (optical density rises), and if the solute enters the cell, there is a return toward initial values (optical density falls) . By this technique sucrose was found to enter cells at a rate approximately one third that of lactose . In addition, the entry of {14C}sucrose was followed by direct analysis of cell contents after separation of cells from the medium by centrifugation . Sucrose accumulated within the cell to a concentration 160% of that in the external medium . The addition of sucrose to an anaerobic suspension of cells resulted in a small alkalinization of the external medium . These data are consistent with the view that the lactose carrier can accumulate sucrose by a proton cotransport system . The carrier exhibits a very low affinity for the disaccharide (150 mM) but a moderately rapid Vmax. J Bacteriol, 1979 Nov, 140(2), 320 - 6 Rhamnose-induced propanediol oxidoreductase in Escherichia coli: purification, properties, and comparison with the fucose-induced enzyme; Boronat A et al.; Escherichia coli are capable of growing anaerobically on L-rhamnose as a sole source of carbon and energy and without any exogenous hydrogen acceptor . When grown under such condition, synthesis of a nicotinamide adenine dinucleotide-linked L-lactaldehydepropanediol oxidoreductase is induced . The functioning of this enzyme results in the regeneration of nicotinamide adenine dinucleotide . The enzyme was purified to electrophoretic homogeneity . It has a molecular weight of 76,000, with two subunits that are indistinguishable by electrophoretic mobility . The enzyme reduces L-lactaldehyde to L-1,2-propanediol with reduced nicotinamide adenine dinucleotide as a cofactor . The Km were 0.035 mM L-lactaldehyde and 1.25 mM L-1,2-propanediol, at pH 7.0 and 9.5, respectively . The enzyme acts only on the L-isomers . Strong substrate inhibition was observed with L-1,2-propanediol (above 25 mM) in the dehydrogenase reaction . The enzyme has a pH optimum of 6.5 for the reduction of L-lactaldehyde and of 9.5 for the dehydrogenation of L-1,2-propanediol . The enzyme is, according to the parameters presented in this report, indistinguishable from the propanediol oxidoreductase induced by anaerobic growth on fucose. Nucleic Acids Res, 1979 Oct 25, 7(4), 971 - 80 A unique method utilizing antinucleotide antibodies for evaluating changes in the levels of modified nucleosides of tRNAs from crude extracts of whole cells; Vold BS et al.; The utilization of antibodies directed toward modified nucleosides in evaluating changes in the levels of certain modified nucleosides in transfer RNA is reported . Antibodies directed toward the N6-(delta 2-isopentenyl)adenosine modification were used in this model system with a mutant strain of Escherichia coli designated ipaA . The procedure is rapid, sensitive, and specific . In addition, it does not depend on the existence of an in vitro remodification system or any radiochemical labeling of the tRNA . By varying the extraction technique, the method could be applied to procaryotic or eukaryotic cell lines . The existence of antibodies specific for other nucleoside modifications makes this a system that is potentially applicable to a variety of deficiencies in the modification of both tRNA and rRNA. Nucleic Acids Res, 1979 Oct 25, 7(4), 879 - 93 The influenza virus haemagglutinin gene: cloning and characterisation of a double-stranded DNA copy; Sleigh MJ et al.; A protocol has been developed for the synthesis of a double-stranded DNA (dsDNA) copy of the influenza virus RNA genome segment which codes for the major surface antigen, haemagglutinin (HA) . This dsDNA copy was inserted, after digestion with S1 nuclease and poly (dC) tailing with terminal transferase, into poly(dG)-tailed, PstI-cut, pBR322 DNA, and used to transform E . coli RR1 . Tetracycline-resistant bacterial colonies were screened for the presence of plasmid containing the copied HA gene by testing their ability to hybridise to a specific, 32P-labelled, single-stranded DNA probe . Four cloned hybrid plasmids, containing DNA complementary to the HA gene of the influenza strain 29C (a laboratory derivative of influenza A/NT/60/68 (1)) were analysed by restriction enzyme mapping . Each contained a dsDNA insert equivalent to a full length copy of the HA gene . The nucleotide sequence of a selected restriction fragment from the DNA inserted in one of these cloned plasmids (C89) was determined . The amino acid sequence deduced from these data agreed with the amino acid sequence determined for the corresponding region of HA from the influenza strain A/Mem/102/72, another member of the Hong Kong subtype, identifying the inserted dsDNA of C89 as an authentic copy of the influenza HA gene. J Biol Chem, 1979 Oct 25, 254(20), 9979 - 81 Precursor maltose-binding protein is active in binding substrate; Ferenci T et al.; Precursor maltose-binding protein synthesized in vitro was shown to be active in binding maltose by affinity chromatography. J Biol Chem, 1979 Oct 25, 254(20), 10237 - 42 The 6-phosphogluconate dehydrogenase reaction in Escherichia coli; de Silva AO et al.; This study is an attempt to relate in vivo use of the 6-phosphogluconate dehydrogenase reaction in Escherichia coli with the characteristics of the enzyme determined in vitro . 1) The enzyme was obtained pure by affinity chromatography and kinetically characterized; as already known, ATP and fructose-1,6-P2 were inhibitors . 2) A series of isogenic strains were made in which in vivo use of thereaction might differ, e.g . a wild type strain versus a mutant lacking 6-phosphogluconate dehydrase, as grown on gluconate; a phosphoglucose isomerase mutant grown on glucose or glycerol . 3) The in vivo rate of use of the 6-phosphogluconate dehydrogenase reaction was determined from measurements of growth rate and yield and from the specific activity of alanine after growth in 1-14C-labeled substrates . 4) The intracellular concentrations of 6-phosphogluconate, NADP+, fructose-1,6-P2, and ATP were measured for the strains in growth on several carbon sources . 5) The metabolite concentrations were used for assay of the enzyme in vitro . The results allow one to calculate how fast the reaction would function in vivo if ATP and fructose-1,6-P2 were its important effectors and if the in vitro assay conditions apply in vivo . The predicted in vivo rates ranged down to as low as one-tenth of the actual rates, and, accordingly, one cannot yet draw firm conclusions about how the reaction is actually controlled in vivo. J Biol Chem, 1979 Oct 25, 254(20), 10139 - 44 The hydrodynamic shape, conformation, and molecular model of Escherichia coli ribosomal 5 S RNA; Fox JW et al.; The structure of ribosomal 5 S RNA has been examined using several physical biochemical techniques . Hydrodynamic measurements yield a s020,omega and {eta} of 5.5 x 10(-13) x and 6.9 ml/g, respectively . Other parameters calculated from these values indicate the shape of 5 S RNA is consistent with that of a prolate ellipsoid 160 A in length and 32 A wide . Sedimentation equilibrium results show that 5 S RNA exists as a monomer in the reconstitution buffer with an apparent molecular weight of 44,000 . Ultraviolet absorption difference spectra show that approximately 75% of the bases in 5 S RNA are involved in base pairing, and of these base pairs 70% are G-C and 30% are A-U . These results on the overall shape and secondary structure of 5 S RNA have been incorporated with the results of other investigators as to the possible location of single-stranded and double-stranded helical regions, and a molecular model for 5 S RNA is proposed . The molecular model consists of three double helices in the shape of a prolate ellipsoid, with two of the double helical regions at one end of the molecule . The structure is consistent with the available data on the structure and function of 5 S RNA and bears similarity to the molecular model proposed by Osterberg et al . ((1976) Eur . J . Biochem . 68, 481-487) based on small angle x-ray scattering results and the secondary structure proposed by Madison ((1968) Annu . Rev . Biochem . 37, 131-148). J Biol Chem, 1979 Oct 25, 254(20), 10128 - 34 High resolution thermal denaturation analyses of small sequenced DNA restriction fragments containing Escherichia coli lactose genetic control loci; Hardies SC et al.; Differential melting curves are reported for four DNA restriction fragments (789, 301, 203, and 95 base pairs in length) spanning the lactose control region . All but the smallest melt with two or more subtransitions . Maps are proposed which identify the positions of regions of different thermal stability in the sequences . The sizes of regions comprising subtransitions range from 60 to 200 base pairs . An analysis is made of the cooperativity exhibited between regions in the sequence . The effect on the shape of the differential melting curves of Na+ between 10 mM and 0.5 M as well as that of Mg2+ and glycerol has been determined . An 81-bp-long sequence of unusual thermal stability occurs at the lactose promoter . Its TM change, resulting from the above change in salt concentration, is out of step by 1.5 degree C with the neighboring DNA sequence . The potential biological significance of this behavior is discussed. Nucleic Acids Res, 1979 Oct 25, 7(4), 859 - 77 Hybrid plasmids containing an active thymidine kinase gene of Herpes simplex virus 1; Wilkie NM et al.; The gene for the thymidine kinase (TK) of Herpes simplex virus type 1 (HSV-1) is located in the KpnI m and BamHI p fragments of the genome (Wigler et al., Cell 11, 223-232 (1977)) . These fragments have been inserted into the EcoRI and BamHI sites, respectively, of plasmid pBR322, and propagated in E.coli . The TK gene contained in the recombinant plasmids was shown to be biologically active when introduced into TK- mouse L cells . Detailed restriction site maps of the BamHI p fragment have been constructed and the approximate location of the TK gene has been determined . Mouse cells transformed with cloned HSV-1 tk+ DNA produced HSV-1-specific thymidine kinase; superinfection with HSV-1 tk- virus increased the level of TK activity tenfold, suggesting that the BamHI p sequences present in transformed cells respond to virus-encoded regulatory gene product(s). J Biol Chem, 1979 Oct 25, 254(20), 10449 - 52 Phosphorylation of 5-iodo-5'-amino-2',5',dideoxyuridine by herpes simplex virus type 1 encoded thymidine kinase; Chen MS et al.; Herpes simplex virus type 1 (HSV-1) encoded thymidine kinase converts 5-iodo-5'-amino-2',5'-dideoxyuridine (AIdUrd), a highly specific anti-herpes agent, into the 5'-diphosphate (AIdUDP) derivative in vitro . AIdUDP was identified by its acid lability, sensitivity to alkaline phosphatase hydrolysis, chromatographic behavior, and ratio of double isotope (125I, 32P) labeling . ATP, but not AMP, is a phosphate donor, and the direct transfer of the beta and gamma phosphate of ATP as pyrophosphate to AIdUrd was ruled out . The presence of a phosphoramidate bond was supported by the acid lability of AIdUDP which has a half life (t1/2) of 320 min at pH 3.0 . At neutral pH, the hydrolysis products are AIdUrd and orthophosphate, with AIdUrd monophosphate being the probable hydrolytic intermediate at these pH values . However, at acidic pH, some pyrophosphate was detected in addition to AIdUrd and orthophosphate . AIdUrd competitively inhibited the phosphorylation of thymidine and deoxycytidine . Escherichia coli thymidine kinase, even though 100-fold higher in activity, was unable to phosphorylate AId-Urd under similar incubation conditions. Nature, 1979 Oct 25, 281(5733), 704 - 6 Ribonucleotides in DNA newly synthesised in 3T6 cells in vivo; Kowalski J et al.; Within the field of DNA replication, considerable interest has focused in recent years on the mechanism of initiation of synthesis of DNA molecules . In vitro replication systems from Escherichia coli have been instrumental in uncovering a priming function fo9r ribonucleotides on the earliest intermediates of DNA polymerisation in vitro and in identifying the proteins involved . In vitro replication systems from mammalian cells that permit the use of the phosphate-transfer method for detection of RNA-DNA junctions as well as direct labelling of the RNA moiety of the molecules have suggested a similar role for ribonucleotides in DNA synthesis in eukaryotes . However, the existence of this mechanism in mammalian cells in vivo has not been established . Here we report the first evidence that a significant proportion of the earliest intermediates in mammalian DNA polymerisation in vivo do, in fact, possess ribonucleotides, presumably because their synthesis was initiated with one or more ribonucleotides. Biochim Biophys Acta, 1979 Oct 24, 580(2), 289 - 97 Studies on the subunits of Escherichia coli coenzyme A transferase . Reconstitution of an active enzyme; Frerman FE et al.; The alpha and beta subunits of the acetyl-CoA:acetoacetate-CoA transferase were purified by isoelectric focusing of the enzyme in the presence of 6 M urea . The purified beta subunit, in which the active center of the enzyme is located, exhibits low catalytic activity (2% of the specific activity of the native enzyme) which is stimulated 5-6-fold in the presence of an equimolar concentration of alpha subunit . The presence of the substrate,acetoacetyl-CoA, is required to recover the catalytic activity of the beta subunit and mixtures containing purified alpha and beta subunits . When the enzyme is dissociation in the presence of 6 M urea and the subunits are not fractioned, removal of the urea by dialysis results in the recovery of 88-98% of enzymic activity and the native alpha2beta2 subunit structure . However, analysis of this renatured enzyme by immunochemical techniques shows that the enzyme does not refold to a completely native conformation . This renatured enzyme exhibits an immunological reactivity more closely resembling the isolated alpha subunit . The results indicate that the alpha subunit serves as a structural subunit, or possible a maturation subunit, imposing a conformation on the beta subunit that is catalytically more competent. Nature, 1979 Oct 18, 281(5732), 544 - 8 Direct expression in Escherichia coli of a DNA sequence coding for human growth hormone; Goeddel DV et al.; DNA coding for human growth hormone was constructed by using chemically synthesised DNA in conjunction with enzymatically prepared cDNA . This 'hybrid' gene was expressed in Escherichia coli under the control of the lac promoter . A polypeptide was produced having the size and immunological properties characteristic of mature human growth hormone. Eur J Biochem, 1979 Oct 15, 100(2), 399 - 410 The complete nucleotide sequence of the ribosomal 16-S RNA from Excherichia coli . Experimental details and cistron heterogeneities; Carbon P et al.; The complete nucleotide sequence of the 16-S RNA from Escherichia coli has been determined using rapid RNA-sequencing gel methods . The experimental data are fully described in this paper . The specificities of the ribonucleases, especially the ribonuclease PhyI are discussed and the consequences of the persistence of stable secondary structure are considered . The proposed sequence contains 1541 nucleotides and agrees completely with the DNA sequence of the rrnB cistron deduced by Brosius, J., Palmer, M.L., Kennedy, P.J., and Noller, H.F . {Proc . Natl . Acad . Sci . U.S.A . (1978) 75, 4801-4805} . But there are several cistron heterogeneities of which we described 16 single-base heterogeneities, 7 of the deletion/insertion type and 9 of the transition or transversion type . Our observations suggest the existence, among the 7 ribosome RNA cistrons, of one or two mutated ones . The respective advantages and disadvantages of both RNA and DNA sequencing methods are discussed. Eur J Biochem, 1979 Oct 15, 100(2), 321 - 8 Arrangement of proteins O-8 and O-9 in outer membrane of Escherichia coli K-12 . Existence of homotrimers and heterotrimers; Ichihara S et al.; 1 . The molecular arrangement of major outer membrane proteins O-8 and O-9 that exist as trimers has been studied by means of cross-linking with dimethylsuberimidate . 2 . The cross-linked samples were examined on a urea/sodium dodecyl sulfate/polyacrylamide gel which was developed to separate cross-linked trimer and dimer of O-8 from those of O-9 . 3 . Cells simultaneously synthesizing both O-8 and O-9 formed heterotrimers (trimers containing both proteins) as well as homotrimers . 4 . Quantitative analyses revealed that there was no discrimination between O-8 and O-9 in the assembly process to form trimers . 5 . When cells were grown sequentially under two different sets of conditions so that the cells synthesized either one of the two proteins in the first stage and the other in the second stage of growth, no heterotrimers were formed . This result indicates that subunit exchange did not take place between trimers which had been incorporated into the outer membrane. Experientia, 1979 Oct 15, 35(10), 1398 - 400 Colony stimulating activity in acute and chronic endotoxinemia in man; Hinterberger W et al.; Blood granulocyte-macrophage colony stimulating activity (GM CSF) was measured in 6 normal individuals challenged with low-dose endotoxin and in 63 unselected patients with nonhaematological disorders . 5/63 patients were febrile and 5 other patients whoed detectable endotoxin levels, as measured by the Limulus assay . CSA levels showed a rapid increase in normal individuals following endotoxin administration, but were in the normal range in patients with chronic endotoxinemia or in those with febrile disorders . Thus, unlike acute endotoxinemia, chronic endotoxinemia is not associated with elevated activity that promotes growth of myeloid commited stem cells . In addition, fever per se did not coincide with elevated blood CSA levels. Tijdschr Diergeneeskd, 1979 Oct 15, 104(20), suppl 4:169 - 75 Detection of the K99 antigen of Escherichia coli in calf faeces by enzyme-linked immunosorbent assay (ELISA); Ellens DJ et al.; An enzyme-linked immunosorbent assay (ELISA) is presented for the detection of the K99 antigen of Escherichia coli in calf faeces . False-positive reactions were not observed with K99-negative strains and with several viral antigens . Only bovine coronavirus caused slight positive reactions which could be eliminated by a blocking test . As compared with the conventional procedure for the detection of the K99 antigen, ELISA seemed to be a least as sensitive and had the advantage that samples could be stored at --20 degrees C before testing . In addition many samples could be handled at the same time and the results became available quickly . By carrying out the assay as a blocking test, specific antibody against K99 in serum or colostrum could be detected and titrated. Experientia, 1979 Oct 15, 35(10), 1318 - 20 Mg2+-ATPase defective mutant of Escherichia coli and thiamine transport; Nishimune T et al.; Mg2+-ATPase deficient mutant of Escherichia coli showed an evident dependency of thiamine uptake on the oxidative metabolism of glucose, whereas the parent strain did not . In both cells, this uptake was completely inhibited by H+ conductors. Biochem J, 1979 Oct 15, 184(1), 13 - 21 Linked transport of phosphate, potassium ions and protons in Escherichia coli; Russell LM et al.; Pi entry into Escherichia coli cells through either of the two Pi-transport systems (Pit or Pst) prompts the influx of K+ and H+ in a ratio that depends on the external pH . The entry of Pi is absolutely dependent on the presence of K+, and the entry of K+ is equally dependent on the presence of Pi . Experiments with a number of mutants carrying any one functional Pi-transport system and one or more of the individual K+-transport systems indicate a permissive type of linkage of the two transports, in that there is no obvious preference by any of the Pi-transport systems for a particular K+-transport system for the concomitant entry of the two ions. Biochim Biophys Acta, 1979 Oct 11, 570(2), 248 - 58 Two forms of pyruvate kinase in Escherichia coli . A comparison of chemical and molecular properties; Valentini G et al.; The two forms of pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40) present in Escherichia coli have been purified from the same cultures and crystallized . A modified procedure for the purification of type I pyruvate kinase is described . Molecular weight, subunit structure, amino acid composition, NH2-terminal amino acid, maps of tryptic peptides and conditions for crystallization have been determined for the two forms . A comparison of these data shows that the two forms are different proteins, each being a tetramer of identical subunits. Nature, 1979 Oct 11, 281(5731), 447 - 52 Directive segregation in the basis of colE1 plasmid incompatibility; Bedbrook JR et al.; Incompatibility between colE1 plasmids in Escherichia coli can be explained by competition for a limited number of replication sites . These sites ensure directive segregation of plasmids to daughter cells on cell division . The number of sites can be more than one only if a linear segregation mechanism is postulated. Nucleic Acids Res, 1979 Oct 10, 7(3), 735 - 49 A rhelogical separator for very large DNA molecules; Dill KA et al.; We present a rheological separation method for DNA molecules in which their deformability is used to advantage . This is the "radial migration method"; here we present experimental verification of the principle, theory having been reported elsewhere . The main conclusions are: (1) the theory is reasonably good; (2) radial migration is highly sensitive to the molecular weight, as predicted, and (3) intact T2 DNA (1.25 X 108 daltons) can be made to migrate about three centimeters in less than three hours. Nucleic Acids Res, 1979 Oct 10, 7(3), 639 - 49 Gene expression in vitro of colicin El plasmid; Ebina Y et al.; Among eighteen polypeptides synthesized in vitro from colicin El plasmid, one of the major products with a molecular weight of 59,000 was identified as colicin El by its immunological property, molecular size, and biological activity . In addition to this polypeptide, seven other polypeptides reacted with colicin El antiserum . Using EcoRI-cleaved colicin El DNA, a 56,000 dalton polypeptide of truncated colicin El was synthesized, but no polypeptide that reacted with colicin El antiserum was produced from SmaI-cleaved colicin El DNA . This fact indicates that the direction of transcription of colicin El structural gene is from SmaI site to EcoRI site in vitro . The immunity protein of a molecular weight of 14,300 and a component of relaxation proteins of a molecular weight of 64,000 were deduced by comparing the results of the gene expression in vitro of one-half (pAO100) and a quarter (pAO2) of colicin El plasmid . The directions of transcription-translation in the genes on the plasmid were discussed . The colicin El plasmid appears to have at least three transcriptional units. J Biol Chem, 1979 Oct 10, 254(19), 9800 - 6 Identification of the amino acid residues of proteins S5 and S8 adjacent to each other in the 30 S ribosomal subunit of Escherichia coli; Allen G et al.; When Escherichia coli 30 S ribosomal subunits are reacted with protein-protein bifunctional reagents, a number of protein pairs as well as aggregates containing three or more ribosomal proteins are formed . In the present study we have purified one of the protein pairs obtained by reaction of 30 S ribosomal subunits with either radioactive or nonradioactive dimethylsuberimidate . Following molecular weight determination and ammonolysis, the pair was shown to consist of ribosomal proteins S5 and S8 . The "native" structure of the complex was surmised from its capacity to be reconstituted into a biologically active 30 S ribosomal subunit . From peptide maps and primary structure determination of various peptides it was demonstrated that the cross-linking bond between ribosomal proteins S5 and S8 involves primarily the residues Lys-93 of protein S8 and the COOH-terminal lysine (Lys-166) of ribosomal protein S5 . This result is substantiated by the finding that a mutant carrying an altered S5 lacking the COOH-terminal lysine yields a greatly reduced amount of S5-S8 cross-link . In addition to the points of cross-linking it was found that Lys-30, Lys-68, and Lys-86 of S8 and Lys-5 of S5 react with dimethylsuberimidate, indicating that these residues are available for reaction and suggesting their topographical localization on the ribosomal surface. J Biol Chem, 1979 Oct 10, 254(19), 9627 - 32 Thioredoxin catalyzes the reduction of insulin disulfides by dithiothreitol and dihydrolipoamide; Holmgren A; Thioredoxin from Escherichia coli was shown to catalyze the reduction of insulin disulfides by dithiothreitol . A quantitative assay was developed which measures the rate of insulin reduction spectrophotometrically at 650 nm as turbidity formation from the precipitation of the free insulin B chain . Thioredoxin, at 5 microM concentration, accelerated the reaction between 0.130 mM insulin and 1.0 mM dithiothreitol at pH 7 around 20-fold . The pH optimum of the reaction was 7.5 . Thioredoxins from E . coli and calf liver showed similar specific activities . Stopped flow fluorescence measurements of the rate of reduction of thioredoxin-S2 by dithiothreitol showed a second order rate constant of 1647 M-1 s-1 at pH 7.2 . This is between 10(2) to 10(3) times larger than the reaction between insulin or linear model disulfides and dithiothreitol . It is consistent with a ping-pong mechanism of thioredoxin catalysis since reduced thioredoxin is known to react very fast with insulin . Thioredoxin also catalyzed lipoamide-dependent reduction of the insulin disulfides in a coupled system with NADH, lipoamide, and lipoamide dehydrogenase . The fast spontaneous reaction between dihydrolipoamide and thioredoxin-S2 provides a mechanism for NADH or pyruvate-dependent disulfide reduction . The implication of the dithiol-disulfide oxidoreductase activity of thioredoxin for the regulation of enzyme activities by thiol oxidation-reduction control is discussed. J Biol Chem, 1979 Oct 10, 254(19), 9429 - 40 ilvU, a locus in Escherichia coli affecting the derepression of isoleucyl-tRNA synthetase and the RPC-5 chromatographic profiles of tRNAIle and tRNAVal; Fayerman JT et al.; A mutation in the ilvU locus of Escherichia coli has led to a complex phenotype that included resistance to thiaisoleucine, a loss of derepressibility of isoleucyl tRNA synthetase, and an alteration of the RPC-5 chromatographic profile of the branched-chain aminoacyl-tRNA's . The alterations were manifest in an increase in the amount of Species 2 of both tRNAIle and tRNAVal at the expense of Species 1 . A similar alteration, but independent of (and additive to) that caused by the ilvU mutation, was observed upon limitation of either isoleucine or valine . The shift in profile caused by limitation was also independent of the reduced growth rate or the derepression of the isoleucine and valine biosynthetic enzymes that also result from limitation . During chloramphenicol treatment nearly all tRNAIle and tRNAVal formed appears as species 2 . Upon recovery from chloramphenicol, Species 2 of both acceptors are converted to Species 1 . It is proposed that the ilvU product not only allows derepression of isoleucyl-tRNA synthetase but also retards the conversion of tRNA2Ile to tRNA1Ile and that of tRNA2Val to tRNA1Val . The mutated ilvU loci abolish the derepression and are more efficient in retarding the conversion. Nucleic Acids Res, 1979 Oct 10, 7(3), 689 - 703 Analysis of RNA secondary structure by photochemical reversal of psoralen crosslinks; Rabin D et al.; Aminomethyltrioxsalen (AMT), a psoralen, is known to cause interstrand crosslinks in double stranded nucleic acids . We have demonstrated the photochemical reversal of this reaction, and have used this result to develop a method for identification of specific sequences which are adjacent because of RNA secondary structure formation . E . coli 5S rRNA is used as a model system . We isolated and characterized a product that is derived from the stem region of 5S RNA. Nucleic Acids Res, 1979 Oct 10, 7(3), 547 - 69 Review: ethidium fluorescence assays . Part 1 . Physicochemical studies; Morgan AR et al.; DNA and RNA can be assayed rapidly and very sensitively by exploiting the enhanced fluorescence of ethidium intercalated into duplex regions . By assaying at different pHs and introducing a heating/cooling cycle, a great many physicochemical aspects of DNA and RNA can be studied avoiding the use of radiolabels, and often giving information not otherwise readily obtainable . Studies are described on duplex DNA which involve measurement of extinction coefficients, cross-linking by chemicals, Cot curve analysis as well as estimation of drug-DNA binding constants . The assays can be adapted to investigate multi-stranded nucleic acid structures . The use of covalently closed circular DNA also allows rapid and extremely sensitive measurements of nicking caused by irradiation or drugs. Med J Aust, 1979 Oct 6, 2(7), 376 - 8 Suppurative pyephlebitis and multiple hepatic abscesses with silent colonic diverticulitis; Waxman BP et al.; This report records the first known case in the literature of suppurative pylephlebitis associated with multiple intrahepatic and extrahepatic abscesses and gross hypoalbuminaemia, as a consequence of colonic diverticulitis. Mol Gen Genet, 1979 Oct 3, 176(2), 233 - 8 IS2-61 and IS2-611 arise by illegitimate recombination from IS2-6; Ghosal D et al.; A more stable derivative of IS2-6 has been isolated, which had lost 54 bp of the 108 bp long insert characteristic of IS2-6 . This new allele of IS2, IS2-61, segregates the remaining 54 bp to yield allele IS2-611 . DNA sequence analysis shows that the segregation products of IS2-6 arise by recA-independent, illegitimate recombination at 9 bp long direct sequence repetitions. Mol Gen Genet, 1979 Oct 3, 176(2), 183 - 9 The DNA-protein relaxation complex of the plasmid RK2: location of the site-specific nick in the region of the proposed origin of transfer; Guiney DG et al.; The broad jost range plasmid, RK2, has been isolated as a DNA-protein relaxation complex . Nicking of the plasmid DNA in the relaxation complex occurs at a single specific site (rlx) located approximately 20 kb away from the origin of DNA replication . A cis-acting function required for plasmid transfer, the presumptive origin of transfer, maps in the same region as rlx . The region of RK2 encompassing rlx has been cloned onto pBR322 and shown to promote mobilization of the hybrid plasmid by an RK2 derivative . These results indicate that the RK2 relaxation complex nicks at or near the origin of transfer of the RK2 plasmid. Mol Gen Genet, 1979 Oct 3, 176(2), 161 - 70 Nucleotide sequence of the region required for maintenance of colicin E1 plasmid; Ohmori H et al.; Plasmids carrying various portions of colicin E1 plasmid (ColE1) DNA have been isolated in an attempt to determine the regions of ColE1 DNA which are required for maintenance of the plasmid in bacteria . To construct the plasmids, the DNA of a ColE1 derivative that contains a gene which controls ampicillin resistance was cleaved by the restriction endonuclease HaeII . The digestion products were joined by T4 DNA ligase and then used to transform bacteria to ampicillin resistance . The plasmid derivatives obtained in this way were always composed of certain HaeII segments . These contain approximately 10% of the ColE1 genome and include the origin of replication of ColE1 . We presume that the region of ColE1 which is common to all these derivatives is required for maintenance of the plasmid . After a description of these results, the nucleotide sequence of this region is presented, and possible roles of the region in plasmid replication and maintenance are discussed. Mol Gen Genet, 1979 Oct 3, 176(2), 209 - 19 Amplification of chloramphenicol resistance transposons carried by phage P1Cm in Escherichia coli; Meyer J et al.; We have characterized a number of P1Cm phages which contain the resistance genes to chloramphenicol and fusidic acid as IS1-flanked Cm transposons . Restriction cleavage and electron microscopic analysis showed that these Cm transposons were carried as monomers (M) or tandem dimers (D) . Lysogens of P1Cm (D) are more resistant to chloramphenicol than those of its P1Cm (M) presumably as a result of an increased gene dosage . Amplification of the Cm transposons to tandem multimers was frequently observed in P1Cm (D) lysogens grown in the presence of high concentrations of chloramphenicol or fusidic acid and was also detected in P1Cm (M) lysogens . The degree of amplification varied in different clones which suggests that cells containing spontaneously amplified Cm transposons were selected by high doses of the antibiotics . The dimeric as well as the amplified Cm transposons carried in P1Cm lysogens grown in the absence of chloramphenicol displayed considerable stability . Mechanisms for the amplification of the IS1-flanked transposons are discussed. Mol Gen Genet, 1979 Oct 2, 176(1), 147 - 9 Identification of a mutation affecting an alanine-alpha-ketoisovalerate transaminase activity in Escherichia coli K-12; Falkinham JO 3rd; A mutation affecting alanine-alpha-ketoisovalerate transaminase activity has been shown to be cotransducible with ilv gene cluster . The transaminase deficiency results in conditional isoleucine auxotrophy in the presence of alanine. Mol Gen Genet, 1979 Oct 2, 176(1), 139 - 46 ColE1 DNA sequences interacting in cis, essential for mitomycin-C induced lethality; Shafferman A et al.; Protein synthesis and survival of colicinogenic bacteria carrying different ColE1 deletion and insertion mutants, were followed in presence or absence of the inducing agent mitomycin-C . It is concluded that active colicin is not involved in the process leading to death of the induced colicinogenic cell . The region of ColE1, essential for cell induced lethality, is carried on the DNA between map positions 0.74 to 0.27 . In this region the DNA sequences carried between 0.74 to 0.79 and 0.0 to 0.27 are essential, while those located between 0.79 to 0.0 are nonessential for commitment to death . A cis interaction of the ColE1 DNA sequences in the essential regions is probably necessary for cell induced lethality . Some possibilities for such a cis interaction are suggested and discussed. Mol Gen Genet, 1979 Oct 2, 176(1), 105 - 11 A cold-sensitive beta subunit mutant RNA polymerase from Escherichia coli with defects in promoter opening in vitro; Larionov OA et al.; A cold-sensitive mutation in the rpoB gene for the RNA polymerase beta subunit increasing the temperature of promoter opening on T2 phage DNA was obtained in Escherichia coli . The mutation also affects the stages preceding promoter opening by increasing the dissociation rate of RNA polymerase--DNA closed complexes . The affinity of RNA polymerase to T2 and lambda DNA is differentially changed by the mutation . The relative efficiency of transcription of these two templates is also changed . These results suggest a participation of the RNA polymerase beta subunit in the interaction with promoters. Mol Gen Genet, 1979 Oct 2, 176(1), 1 - 9 Induction of UV-resistant DNA replication in Escherichia coli: induced stable DNA replication as an SOS function; Kogoma T et al.; The striking similarity between the treatments that induce SOS functions and those that result in stable DNA replication (continuous DNA replication in the absence of protein synthesis) prompted us to examine the possibility of stable DNA replication being a recA+ lexA+-dependent SOS function . In addition to the treatments previously reported, ultraviolet (UV) irradiation or treatment with mitomycin C was also found to induce stable DNA replication . The thermal treatment of tif-1 strains did not result in detectable levels of stable DNA replication, but nalidixic acid readily induced the