Mol Biol (Mosk), 1980 May-Jun, 14(3), 575 - 85 {Gamma-anilides of nucleoside-5'triphosphates as substrates of DNA-dependent RNA-polymerase of Escherichia coli}; Grachev MA et al.; Characteristics of NTP gamma-anilidates (AnpppN) as substrates of E . coli RNA-polymerase have been studied . Michaelis constants for AnpppN are about an order of magnitude greater than those for the usual substrates, whereas the maximum rates differ but unsignificantly . AnpppA is almost completely transformed to polyA and Anppi when synthesis of polyA takes place with AnpppA as the only substrate with denatured DNA as template (reiteration system) . The AnpppA-residue is present at the 5'-terminus of RNA synthesized from AnpppA, CTP, UTP and GTP on T7 DNA template by the holo-enzyme. Mol Biol (Mosk), 1980 May-Jun, 14(3), 558 - 67 {Comparative analysis of affinity modification of several aminoacyl-tRNA synthetases with gamma-(p-azidoanilide)-ATP}; Bulychev NA et al.; The inhibitory action of gamma-(p-azidoanilide)-ATP on the reactions of tRNA aminoacylation catalysed by several aminoacyl-tRNA synthetases was investigated . This compound was shown to be a competitive inhibitor with respect to ATP in the case of arginyl-, valyl-, isoleucyl-, leucyl-, threonyl-, phenylalanyl-tRNA synthetases of E . coli MRE-600 and tryptophanyl-tRNA synthetase of beef pancreas . The Ki value of this analog changes from 3 x 10(-5) up to 4 x 10(-3) M depending on the enzyme specificity . In the case of methionyland lysyl-tRNA synthetases from E . coli the non-competitive and mixed inhibition accordingly was observed . The activity of isoleucyl-, valyl-, leucyl-, threonyl-, phenyl-alanyl- and tryptophanyl-tRNA synthetases in the reaction of tRNA aminoacylation is decreased as a result of UV-irradiation of the enzymes in the presence of gamma-(p-azidoanilide)-ATP . ATP and aminoacids protect these enzymes against irreversible inactivation . These results confirm the affinity labelling of the substrate binding sites of these enzymes . However, the appreciable inactivation of enzymes with UV-irradiation in the presence of gamma-(p-azidoanilide)-ATP was not detected in the cases of hystidyl-, lysyl-, methionyl-, seryl-, tyrosyl- and phenylalanyl-tRNA synthetases of E . coli MRE-600 . The data obtained enable one to suggest the difference in the structure of the amino acid activating sites of different aminoacyl-tRNA synthetases. Mol Biol (Mosk), 1980 May-Jun, 14(3), 531 - 8 {Chemical modification of phenylalanyl-tRNA synthetase and ribosomes of Escherichia coli with derivatives of tRNA-Phe carrying photoreactive groups on guanosine residues}; Vlasov VV et al.; Photoreactive derivatives of tRNAPhe (E . coli) were synthesized by alkylation of the tRNAPhe with 4-(N-2-chloroethyl-N-methylamino)benzylamine and subsequent treatment with 1.4--dinitro-5-fluorophenylazide . The derivatives are active in binding with ribosomes and phenylalanyl-tRNA synthetase when the extent of modification is lower than 3 reactive groups per tRNAPhe molecule . Under irradiation the derivatives modify exclusively the beta-subunit of the phenylalanyl-tRNA synthetase. Mol Biol (Mosk), 1980 May-Jun, 14(3), 520 - 30 {Effect of Escherichia coli mutations affecting the transcription termination rho on the development of T-even phages}; Gintsburg AL et al.; The functionally active transcription termination factor rho is necessary for the T-even phages development . The inactivation of the factor by thermosensitive E . coli gene rho mutations results in blocking phage development . It should be noted that phages T2 and T4 require different levels of this factor's activity . The synthesis of some early proteins diminishes during factor rho inactivation and a number of proteins typical for a later stage are observed early in infection . Under the conditions of the factor rho being inactivated the synthesis of a number of proteins is weakened late in infection and the capside proteins maturation is impaired . Alongside with this the factor rho inactivation results in a sharp decrease of phage DNA replication in infected cells . The obtained data suggests that in the absense of functionally active factor rho all the proteins necessary for phage DNA replication are formed . Besides, this factor is directly involved in the process of T-even phages DNA replication . One may conclude that the inability of T-even phages to develop in mutant cells rho is to a greater extent due to the impairment in phage DNA replication than to its transcription . The possible role of the factor rho in the process of DNA replication is discussed. Mol Biol (Mosk), 1980 May-Jun, 14(3), 507 - 16 {Affinity labeling of ribosomes from Escherichia coli with 4-(N-2-chloroethyl, N-methylamino)-benzaldehyde actyl derivatives of oligouridylates}; Budker VG et al.; 4-(N-2-chloroethyl-N-methylamino)-benzaldehyde acetyl derivatives of penta-., hexa, hepta-, octauridylates were used for localization of the structures organizing the mRNA-binding centre of ribosomes . These derivatives, alike free oligonucleotides, stimulate the binding of phenylalanyl-tRNA to ribosomes . Within the specific complex all the oligonucleotide derivatives alkylated the 30S ribosomal subunit . Octauridylate and hexauridylate derivatives specifically alkylated also the 50S subunit of ribosomes . Polyuridylic acid protected ribosomal subunits from alkylation . In the 30S subunit the derivatives modify 16S RNA and proteins: S4, S5, S7, S9, S13, S15, S18, S21 . It was found that oligouridylate derivatives of different length alkylate different proteins. Mikrobiologiia, 1980 May-Jun, 49(3), 440 - 4 {tRNA methyltransferase activity in Escherichia coli growing on a medium with methionine and S-methylmethionine}; Lebenka AIu et al.; tRNA methylating enzymes isolated from E . coli 113-3 grown in a medium with methionine or S-methylmethionine differed in the activity of transfer of the 14CH3-group from 14CH3-S-adenosyl-L-methionine (SAM) to tRNA in the in vitro experiments in heterological systems consisting of tRNA methyltransferases from E . coli 113-3 and a substrate of methylation, viz . methyl-deficient tRNA isolated from E . coli K 12W6 . In such a system, tRNA methyltransferases from E . coli 113-3 grown on S-methylmethionine methylated tRNA from E . coli K 12W6 at a rate almost twice as high as that in the case of the culture grown on methionine . At the same time, the activity of guanine methylation yielding 7-methylguanine increased significantly . The protein obtained after precipitation of cell-free extracts with ammonium sulfate was separated into four fractions using a system of columns packed with Sephadex G-25 and DEAE-cellulose . These fractions differed quantitatively in culture grown either on methionine or S-methylmethionine. Infect Immun, 1980 May, 28(2), 387 - 92 Analysis of outer membrane components of Escherichia coli ML308 225 and of a serum-resistant mutant; Tee GL et al.; Escherichia coli ML308 225 in the early exponential phase of batch cultures was killed by human serum in a complement-dependent reaction . Under the same conditions, a mutant derived from this strain by multiple subcultures in human serum was resistant to killing by serum . The components of the outer membrane of both the parent and mutant strains were analyzed . The protein and phospholipid analyses were identical, but the mutant strain produced twice as much lipopolysaccharide as the parent strain . These results suggest that the extent of bacterial surface coverage by lipopolysaccharide determines the degree of sensitivity to serum. Eur J Biochem, 1980 May, 106(2), 667 - 74 Photo-induced affinity labeling of Escherichia coli ribosomes by chloramphenicol; Le Goffic F et al.; In order to obtain more information about the binding site for chloramphenicol (D-threo diastereoisomer) on the bacterial ribosome, photo-affinity labeling experiments of this receptor have been performed with {3H}chloramphenicol itself . Control experiments show that this drug can be split photochemically by ultraviolet irradiation, whereas the ribosome is not modified structurally or functionally by such a treatment . When photolysis of a mixture of chloramphenicol and ribosomes is performed under critical conditions, some proteins like L1, L11, S3 and S4 are radiolabeled . L11, S3 and S4 are radiolabeled specifically as demonstrated by photo-incorporation experiments with isotopically diluted {3H}chloramphenicol or by comparison of the results obtained here with reversible experiments performed by the isotopic dilution method . When the D-erythro diastereoisomer of chloramphenicol is photo-incorporated into the bacterial ribosome, proteins are radiolabeled only in a non-specific way . These results show that this material could be used as an efficient scavenger . When finally D-threo {3H}chloramphenicol is photo-incorporated in the presence of a large amount of the D-erythro diastereoisomer, the radiolabeling pattern obtained for the proteins is quite different from that expected: while L11 is still labeled fairly extensively, L27 is the most radiolabeled protein found. Eur J Biochem, 1980 May, 106(2), 495 - 503 A cross-linking study of the Ca2+, Mg2+-activated adenosine triphosphatase of Escherichia coli; Bragg PD et al.; The solubilized Ca2+,Mg2+-activated adenosine triphosphatase of Escherichia coli is composed of five subunits designated alpha, beta, gamma, delta and epsilon in order of decreasing molecular weight . The subunit structure of the enzyme has been investigated by the use of the cleavable cross-linking agents dithiobis(succinimidyl propionate), methyl-4-mercaptobutyrimidate, dimethyl-3,3'-dithiobispropionimidate, disuccinimidyl tartarate, and cupric 1,10-phenanthrolinate . The products of cross-linking were analyzed by two different two-dimensional gel electrophoresis systems . The following cross-linked subunit dimers were observed: alpha 2, beta 2, alpha beta, alpha delta, beta gamma, beta delta, beta epsilon and gamma epsilon . These results, together with other published data, are discussed in relation to a model of the arrangement of the subunits in the ATPase molecule. Eur J Biochem, 1980 May, 106(2), 449 - 56 Quantitative study of the interaction of formylmethionyl-tRNAfMet with ribosomes of Escherichia coli; Ivanov YV et al.; fMet-tRNAfMet binds reversibly to the donor site (P-site) of Escherichia coli ribosomes both in the absence of messenger and in the presence of ApUpGp and some other oligonucleotides or poly(U) . Kinetics of interaction conforms the second-order law . The equilibrium constants and the rate constants of binding are estimated at 0 degrees C . Not only the cognate trinucleotide ApUpGp but also some other oligonucleotides and even poly(U) stimulate the binding . The presence of total deacylated tRNA considerably increases the selectivity of association. Eur J Biochem, 1980 May, 106(2), 361 - 9 Protein mobility inside pyruvate dehydrogenase complexes as reflected by laser-pulse fluorometry . A new approach to multi-enzyme catalysis; Grande HJ et al.; The fluorescence decay curves of the flavin in all pyruvate dehydrogenase complexes studied here are consistent with a two-exponential fit . One of the lifetimes calculated is very short, as demonstrated by experiments in which a mode-locked argon-ion laser was used for excitation . In three complexes out of the four which were investigated, about equal weights for the amplitudes of the two lifetimes are found . In the three-component complex from Azotobacter vinelandii this is not the case . No effects of the protein concentration on the lifetimes of the fluorophore were found in the concentration range studied . A small but significant difference in lifetime is observed for the A . vinelandii complexes when coenzyme-free complex is compared with complex to which Mg2+ and thiamin diphosphate are added . The correlation time calculated from the polarized decay of the flavin fluorescence at 11 degrees C is around 40 ns and 50 ns for A . vinelandii complexes and Escherichia coli complexes respectively . This correlation time is of the same order as the rotational correlation time of free lipo-amide dehydrogenase itself, but much shorter than would be expected from the molecular weights of the complexes . Models explaining the two lifetimes are discussed . A catalytic mechanism based on the internal mobility of the lipoamide dehydrogenase inside the multi-enzyme complex is proposed. Biofizika, 1980 May-Jun, 25(3), 469 - 72 {Proton-potassium exchange in Escherichia coli}; Durgar'ian SS et al.; Energy-dependent proton--potassium exchange in E . coli is suppressed by both ionophores and the inhibitor of hydrogen pumps N,N'-dichlohexilcarbodimide (DCCD) . The ratio of DCCD-sensitive fluxes of H+ and K+ is equal to 2:1 and does not depend upon the values of ionic fluxes, external pH, osmolarity and temperature . Bacteria can absorb synthetic cation tetraphenilphosphonium (TPP+) both in the absence of glucose and at addition of this source of energy . In the presence of glucose TPP+-ions are taken up by cells during the first 5-10 min and then they leave cells . Such glucose--dependent kinetics of TPP+ accumulation coincides with that for the first rapid phase of K+ uptake, but the process is observed, only if the glucose--independent absorption of TPP+ is small . The amount of accumulated TPP+ may be ascribed to the membrane potential of E . coli equalling--180mV . It is therefore considered that electrogenic proton-potassium pump sensitive to external osmolarity operates in E . coli cell membrane and exchanges 2H+ of the cell for 1K+ of external medium. Bol Med Hosp Infant Mex, 1980 May-Jun, 37(3), 425 - 8 {Neonatal aortic thrombosis}; Gutierrez Carreno R et al.; A case of aortic thrombosis is reported in a 14 days old newborn after extensive review of the world literature is made . It was secondary to sepsis and hypercoagulability syndrome . Emphasis is placed on the early diagnosis, on the usefulness of the Doppler system when studying the vascular system as a non-invasive method in critically ill pediatric patients; likewise, on the determinant surgical procedure during the initial stages of the establishment of the aortic thrombosis. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2606 - 10 Homologous pairing in genetic recombination: formation of D loops by combined action of recA protein and a helix-destabilizing protein; Shibata T et al.; Escherichia coli single-strand binding protein (SSB) or phage T4 gene 32 protein reduced the amount of recA protein required to catalyze the formation of D loops from double-stranded DNA and homologous single-stranded fragments . Neither SSB nor gene 32 protein alone catalyzed the formation of D loops, and excessive amounts of either protein, amounts that were sufficient to saturate the single strands, inhibited the formation of D loops completely . Both the stimulatory activity and the inhibitory activity of SSB resisted boiling, which is consistent with the known thermal stability of SSB, whereas the gene 32 protein was inactivated by heating . The formation of D loops in the presence of both recA protein and SSB required homologous DNA and ATP . Spermidine aided the combined action of SSB and recA protein in forming D loops, but Mg2+ alone was sufficient as a counterion. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2592 - 5 Autogenous control of Escherichia coli ribosomal protein L10 synthesis in vitro; Brot N et al.; The DNA-dependent in vitro synthesis of Escherichia coli ribosomal protein L10 was inhibited when L10 was added to the protein-synthesizing incubations . Addition of L10 had little or no effect on the synthesis of ribosomal protein L12, elongation factor Tu (tufB), or the beta and beta' subunits of RNA polymerase . In addition, ribosomal protein L12 did not inhibit its own synthesis or the synthesis of L10 . Experiments using a mRNA-directed system showed that the inhibition of the synthesis of L10 by itself is at the level of translation of protein synthesis . The mechanism of inhibition does not appear to be due to increased degradation of L10 mRNA. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2434 - 8 Structural studies of methyl-accepting chemotaxis proteins of Escherichia coli: evidence for multiple methylation sites; Chelsky D et al.; Two-dimensional analysis of tryptic peptides from {35S}methionine-labeled methyl-accepting chemotaxis proteins, MCP I and MCP II, demonstrates a high degree of homology between the two proteins . After the methylation sites were labeled with S-adenosyl-L-methyl-3H}methionine, peptides of three distinct migrations in each protein were found to carry a methyl group . These multiple methylations appear to be responsible in part for the observed multiple banding patterns on sodium dodecyl sulfate/polyacrylamide slab gels. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2390 - 4 DNA synaptase: an enzyme that fuses DNA molecules at a region of homology; Potter H et al.; This paper describes an enzyme from Escherichia coli, and its purification to apparent homogeneity . The protein, which we call "DNA synaptase" and which may be representative of a class of enzymes, fuses double-stranded DNA molecules at a region of homology . In addition, the purified enzyme is able to catalyze the association of single-stranded DNA with homologous duplex DNA . The genome fusion reaction catalyzed by the purified enzyme occurs in the presence of Mg2+, spermidine, and 2-mercaptoethanol and does not require a high-energy cofactor . By bringing two genomes together at a region of homology, DNA synaptase has a property expected for an enzyme that participates in an early step in genetic recombination . However, the synaptase can be recovered from Rec A- cells, and thus it is not yet possible to determine whether this enzyme plays a role in physiological recombination or in another cellular process that involves genome fusion, such as the recombinational repair of damaged DNA. Chem Biol Interact, 1980 May, 30(2), 203 - 7 Comparative mutagenicity of linear and angular furocoumarins in Escherichia coli strains deficient in known repair functions; Venturini S et al.; Four furocoumarins, two having a linear molecule, psoralen and 8-methyl-psoralen and two having an angular molecule, angelicin and 4,5'-dimethyl-angelicin were tested for mutagenesis in Escherichia coli B wild type and in various strains deficient in known repair systems . The results indicate that both monoadducts and crosslinks are mutagenic . The mutagenic efficiency of the furocourmarins ranks in the following order 8-methylpsoralen psoralen greater than angelicin greater than 4,5'-dimethylangelicin. J Med Microbiol, 1980 May, 13(2), 265 - 71 Passive protection of lambs against enteropathogenic Escherichia coli: role of antibodies in serum and colostrum of dams vaccinated with K99 antigen; Morris JA et al.; Lambs from suckling ewes vaccinated with the K99 antigen were resistant to challenge with K99-positive enteropathogenic Escherichia coli . Serum and colostrum from these ewes were compared with samples from control ewes to establish methods for monitoring vaccination and to determine the mechanism of protection . Vaccination stimulated production of K99 antibodies . These could be detected by an indirect haemagglutination test and a haemagglutination-inhibition test . Antiglobulin and gel-diffusion tests were less reliable . Experiments with brush-border cells from calf intestine showed that the antibodies were associated with anti-adhesive activity . The antibodies were predominantly IgG and did not neutralise the activity of heat-stable enterotoxin . It was concluded that neutralisation of the adhesive properties of the K99-positive E . coli by colostral antibodies significantly contributed to the resistance of the lambs from vaccinated ewes. J Bacteriol, 1980 May, 142(2), 615 - 20 Organization of genes in the ftsA-envA region of the Escherichia coli genetic map and identification of a new fts locus (ftsZ); Lutkenhaus JF et al.; Complementation tests have revealed that the mutation in the filamenting mutant PAT84 is distinct from ftsA and has been designated ftsZ . By isolating transducing phages carrying various amounts of the bacterial deoxyribonucleic acid in this region, it was possible to locate the ftsZ gene between ftsA and envA . It is concluded that these cell division genes are expressed independently of the neighboring murein genes. J Bacteriol, 1980 May, 142(2), 535 - 46 Effect of the uvrD mutation on excision repair; Kuemmerle NB et al.; A pair of related Escherichia coli K-12 strains, one of which contains the uvrD101 mutation, were constructed and compared for ability to perform various steps in the excision repair of deoxyribonucleic acid damage inflicted by ultraviolet radiation . The results of this study indicated: (i) ultraviolet sensitivity in the uvrD101 mutant was greater than that of wild type but less than that measured in an incision-deficient uvrA mutant; (ii) host cell reactivation paralleled the survival data; (iii) postirradiation deoxyribonucleic acid degradation was virtually identical in the two strains; (iv) incision, presumably at the sites of pyrimidine dimers, proceeded normally in the uvrD101 strain; (v) excision of pyrimidine dimers was markedly reduced in both rate and extent in the uvrD101 mutant; (vi) the amount of repair resynthesis was the same in both strains, and there was no evidence of abnormally long repair patches in the uvrD mutant; and (vii) rejoining of incision breaks was slow and incomplete in the uvrD strain . These data suggest that the ultraviolet sensitivity conferred by the uvrD mutation arises from inefficient removal of pyrimidine dimers or from failure to close incision breaks . The data are compatible with the notion that the uvrD+ gene produce affects the conformation of incised deoxyribonucleic acid molecules. J Bacteriol, 1980 May, 142(2), 527 - 34 Tumbling chemotaxis mutants of Escherichia coli: possible gene-dependent effect of methionine starvation; Kondoh H; Some mutants defective in chemotaxis show incessant tumbling behavior and are called tumbling mutants . Previously described tumbling mutations lie in two genes, cheB and cheZ (41.5 min on Escherichia coli map) . Genetic analysis of various tumbling mutants, however, revealed that two more genetic loci, cheC (43 min) and cheE (99.2 min), could also mutate to produce tumbling mutants . The genetic map around cheC was revised: his flaP flaQ flaR flbD flaA (= cheC) flaE . flbD is a new gene . When cells were starved for methionine, the tumbling mutants changed their swimming behavior depending on the che gene mutated . cheZ mutants, like wild-type bacteria, ceased tumbling shortly after removal of methionine . The tumbling of cheB or cheE mutants was depressed after prolonged methionine starvation in the presence of a constant level of an attractant . cheC tumbling mutants appeared unique in that they did not cease tumbling even when cells were deprived of methionine . By contrast, arsenate treatment of the tumbling mutants resulted in smooth swimming of the cells in every case . These results suggest that two different processes are involved in regulation of tumbling; one requiring methionine and the other requiring some phosphorylated compound. J Bacteriol, 1980 May, 142(2), 462 - 6 Integrative compatibility: stable coexistence of chromosomally integrated and autonomous derivatives of plasmid RP4; Watson MD et al.; P group plasmid RP4 lambda att has a novel feature . Its incompatibility function is phenotypically switched off when it integrates into the bacterial chromosome. Gastroenterology, 1980 May, 78(5 Pt 1), 1001 - 4 Endotoxemia of cirrhosis: an observation not substantiated; Fulenwider JT et al.; Physiologic similarities between cirrhotic and septic patients have implicated systemic endotoxemia as a possible mediator of the hemodynamic, neurologic, and hematologic complications observed in patients with cirrhosis of the liver . The recently reported high prevalence of endotoxin in ascites, as well as in portal and systemic plasma, has further incriminated endotoxin of gut origin as the responsible agent . Limulus amebocyte lysate tests were performed upon peripheral plasma of 38 cirrhotic patients; portal plasma and ascites were assayed in 14 and 11 of these patients, respectively . No endotoxin was detectable . We believe that the ubiquity of endotoxin, with the attendant opportunities for specimen contamination, is the most likely explanation for the recently reported high prevalence of endotoxin in the plasma and ascites of cirrhotic patients. J Virol, 1980 May, 34(2), 438 - 45 Rescue of abortive T7 gene 2 mutant phage infection by rifampin; Ontell MP et al.; Infection of Escherichia coli with T7 gene 2 mutant phage was abortive; concatemeric phage DNA was synthesized but was not packaged into the phage head, resulting in an accumulation of DNA species shorter in size than the phage genome, concomitant with an accumulation of phage head-related structures . Appearance of concatemeric T7 DNA in gene 2 mutant phage infection during onset of T7 DNA replication indicates that the product of gene 2 was required for proper processing or packaging of concatemer DNA rather than for the synthesis of T7 progeny DNA or concatemer formation . This abortive infection by gene 2 mutant phage could be rescued by rifampin . If rifampin was added at the onset of T7 DNA replication, concatemeric DNA molecules were properly packaged into phage heads, as evidenced by the production of infectious progeny phage . Since the gene 2 product acts as a specific inhibitor of E . coli RNA polymerase by preventing the enzyme from binding T7 DNA, uninhibited E . coli RNA polymerase in gene 2 mutant phage-infected cells interacts with concatemeric T7 DNA and perturbs proper DNA processing unless another inhibitor of the enzyme (rifampin) was added . Therefore, the involvement of gene 2 protein in T7 DNA processing may be due to its single function as the specific inhibitor of the host E . coli RNA polymerase. Ann Surg, 1980 May, 191(5), 626 - 35 Cholecystitis, cholelithiasis and common duct stenosis in children and adolescents; Holcomb GW Jr et al.; A study of 100 patients from 14 months through 18 years of age with extrahepatic biliary tract conditions who have been treated from 1950 through 1979 is reported . For discussion, these have been classified into four groups including acalculous cholecystitis, nonhemolytic cholelithiasis, hemolytic cholelithiasis and stenosis of the common duct . Ninety-nine patients were operated on and there were no deaths . Except for unusual contraindications, cholecystectomy is preferred for acute noncalculous cholecystitis . The largest number having gallstones were those patients (87%) without hemolytic disease . Only 13% had an associated hemolytic disorder . Cholecystectomy is the preferred treatment and common duct exploration is utilized when indicated . Six children with chronic relapsing pancreatitis secondary to stenosis of the ampulla of Vater and two with common duct stenosis are analyzed . Although extrahepatic biliary disorders are usually not considered in the differential diagnosis of children and adolescents with vague abdominal pain, it is evident by this large number of patients that there should be greater emphasis placed on earlier diagnosis in the future. Am J Obstet Gynecol, 1980 May 1, 137(1), 53 - 7 The role of prostaglandins in endotoxemia: comparisons in response in the nonpregnant, maternal, and fetal models . I . Prostaglandins and the pulmonary effect of experimental endotoxemia; Cefalo RC et al.; The mechanism of respiratory distress in sepsis is unknown . Previous work has shown elevations of prostaglandins during sepsis . This study reveals a correlation between levels of prostaglandins F 2 alpha and E and pulmonary hypertension and other parameters of respiratory distress in oophorectomized ewes subjected to endotoxin . The use of prostaglandin synthetase inhibitors prior to endotoxin prevented the rise in prostaglandins and the development of respiratory distress. Surgery, 1980 May, 87(5), 588 - 92 Mechanisms of the adjuvant effect of hemoglobin in experimental peritonitis . III . The influence of hemoglobin on phagocytosis and intracellular killing by human granulocytes; Hau T et al.; The effect of hemoglobin on the ability of polymorphonuclear granulocytes (PMNs) to phagocytize and kill opsonized E . coli was measured . Results show that the addition of hemoglobin in a concentration of 0.1% inhibititis phagocytotic activity of PMNs from 68% to 13% after 30 minutes and from 73% to 45% after 60 minutes . The rate of intracellular killing after the addition of hemoglobin in the concentration of 0.5% declined from 63% to 21% . Though these experiments do not allow any conclusions as to the exact mechanism of action of hemoglobin in inhibition of phagocytosis, it seems likely from other data that the inhibitory activity resides in the heme part of the molecule . We conclude that hemoglobin inhibits phagocytotic activity and the ability to kill ingested bacteria of human polymorphonuclear granulocytes . This provides an additional mechanism for the adjuvant action of hemoglobin in intraperitoneal infections and supports the theory that hemoglobin acts directly on the granulocyte to impair the essential host defenses. J Trauma, 1980 May, 20(5), 410 - 2 Protective effect of a splenic extract in mice with endotoxemia; Spillert CR et al.; We have previously described the isolation of a lipoidal splenic extract (LSE) that demonstrated a variety of hematologic effects including inhibition of platelet aggregation both in vivo and in vitro . Since endotoxin causes platelet aggregation and microembolism the protective effect of LSE in endotoxemia was examined in the present study . Both young and elderly Swiss mice given LSE 2--3 hours before endotoxin challenge showed a statistically significant increase in survival compared with saline-treated controls . However, no significant improvement in survival was noted when LSE was administered at the same time as endotoxin . These results add further support to the role of the spleen in the control of infection. J Immunol, 1980 May, 124(5), 2117 - 21 Mitogen-induced plasma cell differentiation in patients with multiple sclerosis; Levitt D et al.; Cellular interactions involved in mitogen-stimulated plasma cell differentiation were investigated in eight patients with severe but stable multiple sclerosis (MS) . No significant differences were detected between normals and MS patients with regard to percent of B lymphocytes and T lymphocytes in peripheral blood . Autologous and allogeneic combinations of normal and MS B and T cells were stimulated with pokeweed mitogen (PWM) and E . coli lipopolysaccharide (LPS), and plasma cell differentiation was monitored after 7 days in culture . T lymphocytes from patients with MS induced 2- to 4-fold increases in plasma cell development when combined with normal B cell fractions . Allogeneic combinations on normal B and T cells did not provide enhanced plasma cell generation . B lymphocytes from MS patients exhibited poor responses to both PWM and LPS when cultured with their own or normal T cells . Such B cell fractions did not differ from normals with regard to percent monocytes or surface Ig+ B lymphocytes initially contained in these cell populations . We conclude that T cells from MS patients are able to provide excessive help for normal B cell differentiation due either to increased T helper activity or deficient T suppressor activity . B cell differentiation may be diminished in MS patients as a result of a deficiency of a population of B cells in blood that are able to be stimulated by polyclonal B cell activators. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2611 - 5 Sequences of the recA gene and protein; Sancar A et al.; We have determined the nucleotide sequence of the recA gene of Escherichia coli; this permits the formulation of the primary structure for the recA protein . This structure is consistent with the amino acid composition of the tryptic peptides obtained from the recA protein . The coding region of the recA gene has 1059 base pairs, which specify 352 amino acids . The recA protein has alanine and phenylalanine as its NH2- and COOH-terminal amino acids, respectively, and has the following amino acid composition: Cys3 Asp20 Asn15 Met9 Thr17 Ser20 Glu30 Gln13 Pro10 Gly35 Ala38 Val22 Ile27 Leu31 Tyr7 Phe10 His2Lys27 Trp2 Arg14 . Of the three cysteine residues, only two can be alkylated under reducing and denaturing conditions . The molecular weight of the recA polypeptide is 37,842. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2445 - 9 Sequences of two kinetoplast DNA minicircles of Tryptanosoma brucei; Chen KK et al.; Kinetoplast DNA of Trypanosoma brucei is composed of a network of about 10,000 interlocked minicircle DNA molecules (1.0 kilobase) that are catenated with about 50 maxicircle DNA molecules (23 kilobases) . Several different DNA . DNA hybridization techniques using individual minicircle DNA sequences cloned in Escherichia coli have indicated that each minicircle molecule contains about one-fourth of its sequence in common with most other minicircles and the remaining three-fourths in common with about 1 out of every 300 minicircles . We have determined the complete sequence of two cloned minicircle DNA molecules that were released from the total kinetoplast DNA network by different restriction enzymes; one minicircle is 1004 base pairs long, the other is 983 base pairs . Both are about 72% dA + dT . They share about 27% of their sequences; the largest continuous region in common is 122 base pairs of near-perfect homology . Twelve other regions of perfect homology equal to or greater than 10 base pairs are also present . Both sequences contain a large number of translation termination codons in all potential translation reading frames . The largest oligopeptide potentially specified by one minicircle sequence is 52 amino acids; the largest by the other minicircle sequence is 71 amino acids . One minicircle contains a decanucleotide sequence that is repeated in tandem five times . It is proposed that massive recombination among the interlocked minicircles in the kinetoplast DNA network may account for much of the homology observed in the two minicirce sequences. Eur J Biochem, 1980 May, 106(1), 313 - 20 Identification of a class of lysines within the non-specific DNA-binding site of RNA polymerase core enzyme from Escherichia coli; Makoff AJ et al.; The imido ester, methyl acetimidate, which specifically amidinates lysine residues, modifies RNA polymerase core enzyme, leading to rapid loss of activity . Calf thymus DNA partially protects the enzyme against this inactivation, an effect which disappears at high salt concentration . DNA protects 17 +/- 6 lysines from amidination at low salt concentration . The dependence of amidination on methyl acetimidate concentration is examined in the presence of DNA at high and low salt concentration . Analysis of the data suggests a class of approximately 12 lysines which are protected by DNA, consistent with the above estimate . These lysines are approximately 5--10-fold more reactive than most other available lysine residues. Ann Immunol (Paris), 1980 May-Jun, 131C(3), 397 - 404 Immunosuppression associated with erythropoiesis in genetic low responder mice; Conway de Macario E et al.; Priming-memory generation in response to Escherichia coli beta-D-galactosidase occurs without antibody formation in irradiated spleen-cell-transferred C57BL/6J mice, which are genetic low responders to the enzyme . Erythropoiesis abolishes priming-memory generation, so that recipients immunized a few days after cell transfer and erythropoiesis induction do not mount a secondary antibody response . Priming-memory generation in cell recipients immunized 3 days after erythropoiesis induction was less frequent than in controls, whereas no significant differences were found when antigen was given before erythropoiesis induction or 5 days after it . The mean titre of the mice escapint suppression was similar to that of the control mice, which became primed and mounted memory . The titre distribution in both responder groups were also similar, although no high-titered responders were found in the erythropoietic mice . Thus while erythropoiesis induction affects the frequency of priming-memory generation, it does not affect to the same extent the amount of memory generated in those mice escaping suppression . The same distinction was observed when spleen cells from erythropoietic mice, containing 30 to 40% erythroblasts, were transferred into normal mice . However, induction of erythropoiesis in non-irradiated non-cell=transferred mice did not cause suppression. Z Naturforsch {C}, 1980 May-Jun, 35(5-6), 522 - 5 On the reactivity of pyridoxal-5'-phosphate with yeast tRNAPhe and tRNATyr; Okabe N et al.; Yeast tRNAPhe and tRNATyr were reacted with the fluorescent reagent pyridoxal-5'-phosphate and the modified tRNAs were analysed with respect to the number and position of modified nucleosides and with respect to aminoacylation . a) Following the intrinsic fluorescence of pyridoxal-5'-phosphate, the treatment of tRNATyr with increasing amounts of pyridoxal-5'-phosphate revealed about 50 mol or reagent or a even higher number bound per one mol of tRNATyr . After borohydride reduction (in order to stabilize the linkage) of this modified tRNATyr and purification with reverse phase chromatography a modified tRNATyr was obtained carrying about 2 mol of the reagent . b) Both tRNATyr and tRNAPhe treated with pyridoxal-5'-phosphate and reduced exhibited almost unchanged aminoacylation as compared to the unmodified tRNAs . c) Pyridoxal-5'-phosphate treated and reduced tRNAPhe and tRNATyr were digested with ribonuclease T1 and the resulting oligonucleotides were separated . However, no fluorescent oligonucleotide and no difference to an oligonucleotide pattern obtained from unmodified tRNA were observed . Thus, pyridoxal-5'-phosphate might have been bound to the highly purified yeast tRNAPhe and tRNATyr samples either via an unstable linkage or not covalently . This result is controversial with respect to the specific reaction of pyridoxal-5'-phosphate with unfractionated tRNAs from colon carcinoma and tRNAs from E . coli as reported in the literature. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2819 - 23 DNA-damaging agents stimulate gene expression at specific loci in Escherichia coli; Kenyon CJ et al.; Operon fusions in Escherichia coli were obtained that showed increased beta-galactosidase expression in response to treatment with the DNA-damaging agent mitomycin C . These fusions were generated by using the Mud(ApR, lac) vector {Casadaban, M.J . & Cohen, S.N . (1979) Proc . Natl . Acad . Sci . USA 76, 4530-4533} to insert the lactose structural genes randomly into the bacterial chromosome . Induction of beta-galactosidase in these strains, which carried fusions of lac to these din (damage-inducible) loci, was (i) triggered by UV light as well as by mitomycin C and (ii) abolished by either a recA- or a lexA- mutation . Similar characteristics of induction were observed when the lactose genes were fused to a prophage lambda promoter by using Mud(ApR, lac) . These results indicate that E . coli contains a set of genes that, like prophage lambda genes, are expressed in response to DNA-damaging agents and regulated by the recA and lexA gene products . These din genes map at five bacterial loci . One din::Mud(ApR, lac) insertion results in a UV-sensitive phenotype and may be within the uvrA transcriptional unit. J Bacteriol, 1980 May, 142(2), 732 - 4 Positions of early nonsense and deletion mutations in lacZ; Welply JK et al.; The positions of three Escherichia coli lacZ operator-proximal nonsense mutations and one deletion mutation have been determined . The nonsense mutations were suppressed with supF, resulting in the production of active beta-galactosidase by each strain . Amino acid sequencing identified the positions of the tyrosine residues inserted by supF, and thereby established that nonsense mutations lacZ2, lacZ2246, and lacZU131 are at sites corresponding to amino acids 23, 36, and 41 of beta-galactosidase, respectively . The deletion mutant, lacZM112, produced a dimeric beta-galactosidase protein missing amino acid residues 23 through 31 of the native enzyme. J Nucl Med, 1980 May, 21(5), 480 - 3 Modifications in biphasic liquid-scintillation vial system for radiometry; Ganatra RD et al.; Several modifications of the biphasic liquid-scintillation vial system for radiometry have been tried in order to improve the counting efficiency . The biphasic system consisted of an inner sterile vial containing medium and substrate, and an outer liquid-scintillation vial lined on the inside with filter paper impregnated with scintillation fluors and alkali . The system gave an overall counting efficiency of 14.6% . Substitution of methanolic NaOH for impregnation of the paper raised the counting efficiency to 29.1% . This could be further enhanced to 33.8% by lining only half of the outer vial with filter paper, thereby allowing improved optical transmission of scintillation light . Increasing the amount of fluor did not change the efficiency significantly . A complete interchange in the system, whereby half of the inner vial was lined with filter paper and was otherwise empty, while the outer vial contained the medium and substrate, gave the highest efficiency (36.9%) . This also allowed the use of larger amounts of medium and the inoculum. Appl Environ Microbiol, 1980 May, 39(5), 1046 - 53 Temperate coliphages: classification and correlation with habitats; Dhillon EK et al.; Temperate coliphages were recovered from sewage, mammalian feces, and lysogenic strains of Escherichia coli . A total of 32 phages of independent origin were divided into six groups by applying the criteria of host range, antigenic homology, and the ultraviolet inducibility of the prophage . The demonstration of genetic interactions in some cases has confirmed the classification scheme . Nine phages were assigned to the P2 family and 19 to the lambda family . The remaining four isolates may represent some novel phylogenetic types . Phages recovered from the lysogenic strains of E . coli were all found to be P2 related, whereas a majority of the phages recovered as cell-free plaque-forming units were assignable to the lambda family . It is proposed that the biological attributes of the phages belonging to the two principal families are reflected in the distribution patterns observed . The virions of phage HK256 show multiple tail fibers and may thus represent a "new" virion form among the temperate coliphages. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2621 - 5 DNA sequence encoding the NH2-terminal peptide involved in transport of lambda receptor, an Escherichia coli secretory protein; Hedgpeth J et al.; lamB encodes the lambda receptor of Escherichia coli, an outer membrane protein . We have identified the beginning of the lamB gene by correlating DNA nucleotide sequence with a partial sequence of the primary translation product of lamB . We show that lambda receptor is synthesized as a precursor containing an extra 25 amino acids at its NH2 terminus . These amino acids are predominately hydrophobic and probably comprise a structure required for initiation of transport of lambda receptor from the cytoplasm to the outer membrane. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2569 - 73 Recognition of duplex DNA containing single-stranded regions by recA protein; West SC et al.; Genetic recombination in Escherichia coli requires recA protein, the product of the recA+ gene . In this paper we show that purified recA protein, which binds strongly to denatured DNA, cooperatively recognizes DNA containing short single-stranded regions . The interaction of varying amounts of recA protein with DNA molecules was investigated by measuring its DNA-dependent ATPase activity . In 3mM Mg2+, the ATPase activity was stimulated by excess single-stranded DNA and was minimal with either intact circular or blunt-ended linear duplexes . Single-strand gaps of about 30 nucleotides were sufficient to increase the ATPase activity to a level almost as great as that observed with single-stranded DNA . Sedimentation studies at neutral pH showed cooperative binding of recA protein to single-stranded DNA or to duplex DNA containing single-stranded regions . In the presence of ATP, an intermediate rate of sedimentation was observed; in contrast, adenosine 5'-gamma-thiotriphosphate (ATP{S}) caused the formation of fast-sedimenting DNA-protein complexes . Gapped plasmid DNA plus recA protein and ATP{S} formed large aggregates containing thousands of molecules . Complex formation and stimulation of the ATPase activity of recA protein with duplex DNA containing single-stranded regions indicates that recA protein may change the conformation of the normally duplex molecules to a conformation prepared for homologous pairing. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2519 - 23 Stimulatory effect of low ATP pools on transport of purine nucleosides in cells of Escherichia coli; Munch-Petersen A et al.; Cells of Escherichia coli contain two nucleoside-transport systems . Energy-starved cells of a strain containing only one of these systems and, in addition, carrying a mutation in the Ca2+- and Mg2+-dependent ATPase (ATP phosphohydrolase 3.6.1.3) are still able to transport nucleosides . The rate is only slightly lower than the rate measured in unstarved cells . Freshly harvested uncA cells transport purine nucleosides at a higher rate than cells from the isogenic strain containing a functional ATPase . If cells from the latter strain are treated with arsenate, transport rates increase to the same levels as found in uncA cells . The presence of an uncA mutation has no effect on the transport rates for cytidine, deoxycytidine, and uridine, nor has arsenate treatment . These findings indicate that ATP is not required as energy donor for nucleoside transport . The enhanced transport rate for purine nucleosides after treatment with arsenate seems to suggest a regulatory relationship between the transport of these nucleosides and the cellular levels of ATP or a closely related metabolite. Eur J Biochem, 1980 May, 106(1), 179 - 92 Nucleotide sequence of the simian virus 40 HindII + III restriction fragment I (fourth part of the T antigen gene); Van Herreweghe J et al.; The HindII + III restriction fragment I (Hind-I) from simian virus 40 DNA represents 4.96% of the genome and maps in the early transcription region . Hind-I is an internal segment of the A gene and its information is expressed as part of the early 19-S mRNA, which codes for T antigen . We report here the nucleotide sequence of the 259-base-pair Hind-I fragment . The sequence was determined and confirmed by RNA and DNA sequencing methods: by analysis of oligonucleotides resulting from T1 and pancreatic RNase digestion of labeled RNA transcribed from SV40 DNA with Escherichia coli DNA-dependent RNA polymerase, by partial degradation of RNA transcripts with snake venom phosphodiesterase, and by base-specific chemical degradation of 5'-end-labeled subfragments of Hind-I according to the procedure of Maxam and Gilbert . Multiple triplets corresponding to termination codons occur in two of the three reading frames of the DNA strand that has the same polarity as early mRNA . The open reading frame connects in phase with the one of the Hind fragments flanking Hind-I, and the amino acid sequence specified by Hind-I lies in the middle part of the large-T antigen . Some features of the primary nucleotide sequence and of early transcription are discussed. Arch Dis Child, 1980 May, 55(5), 376 - 9 Oral rehydration therapy for treatment of rotavirus diarrhoea in a rural treatment centre in Bangladesh; Taylor PR et al.; PIP: The outcome of a rehydration treatment used during a 40-day period at a WHO Center in Bangladesh on 216 children under age 5 is reported . In addition, an enzyme-linked immunosorbentassay (ELISA) designed to detect rotavirus in stool specimens is described and its application explained . The ELISA assay was adaptable to use in a rural treatment center . In a 40-day period, using the new virus-detecting assay, rotavirus without other pathogens was found in stools of 216 (45%) of 480 children who attended the center with gastrointestinal illness . Of these 216 children with only rotavirus pathogen, 188 were treated with oral rehydration alone (oral glucose solution prepared according to WHO procedures); 28 required additional intravenous rehydration therapy . No deaths occurred . 95% of the cases were judged successful on oral rehydration alone for gastrointestinal effects of rotavirus infection . No serious side effects were reported . This oral glucose solution is now indcated in E . coli (enter otoxin)-mediated diarrhea as well as in rotavirus-induced diarrhea . Ann Microbiol (Paris), 1980 May-Jun, 131(3), 233 - 47 The lactose transposon Tn951: characterization of transposition; Cornelis G et al.; Transposition of the lactose transposon Tn951 was found to still occur in the absence of its original host plasmid pGC1 . Transposition was recA-independent . These results show that Tn951 is indeed a transposon . A computer program was developed to facilitate mapping of transposon integration sites in plasmids from restriction data. Mol Biol (Mosk), 1980 May-Jun, 14(3), 615 - 23 {Cloning of fragments of lambda phage DNA, containing red and gam genes}; Khodkova EM et al.; On the base of plasmid pCV20 (Apr, Tcr mol . weight 5.2 x 10(6) a recombinant plasmid pEH60 (Apr, mol . weight 17.0 x 10(6) with BamHI fragment of phage DNA, containing red+ and gam+ genes was constructed . Selection was found on the ability of phage red- and gam- to propagate in strain E . coli K12 recA-, which was transformed by recombinant plasmid with active red and gam genes . Influence of recombinant plasmid pEH60 on processes of repair and recombination of phage lambda DNA and bacterial DNA was studied . It was shown that red gene in plasmid pEH60 compensates deficiency of redA gene in these processes with phage lambda DNA; in the case of E . coli K12 AB2480 uvr- recA- (pEH60) the processes of multiple reactivation and decombination of phage red- were presented . In the case of bacterial cells, plasmid pEH60 did not compensate deficiency of recA function of bacteria, although it partly compensates deficiency of recBC function . Increase of survival after introduction of plasmid pEH60 in the cell was obtained only for recBC- strain, but not for wild type and recA- strains. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2814 - 8 Recombination genes on the Escherichia coli sex factor specific for transposable elements; Hopkins JD et al.; The Escherichia coli sex factor stimulates precise excision of transposons Tn5 and Tn10 from sites either within the bacterial chromosome or within the factor itself . We have isolated two kinds of mutations that affect this activity . The ferA mutations eliminate the stimulation; the ferB mutations enhance it in the presence of FerA+ . We conclude that ferA defines a sex factor gene that stimulates precise excision . The ferB mutations also specifically increase the rate of recombination between two IS3 elements on F' lac-pro (F'128) in a reaction that requires the product of recA . The stimulation of this recombination by ferB also requires an active ferA gene, which implies that the ferA gene stimulates this reaction as well as precise excision . A ferA mutation was mapped at 84.2 kilobases on the F factor, and a ferB mutation was mapped at 82.5 kilobases . The fer mutants were obtained by an approach that permits the isolation of mutants affecting precise excision. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2626 - 30 Acetate kinase: a triple-displacement enzyme; Spector LB; Facts relating to the mechanism of phosphoryl transfer by acetate kinase (ATP:acetate phosphotransferase, EC 2.7.2.1) are reviewed . They point to the existence of at least one experimentally established phosphoenzyme (E-P) intermediate on the reaction pathway . Sterically, the phosphoryl transfer occurs with a net inversion of the configuration of the phosphorus atom . These facts are best in accord with a triple-displacement mode of action for acetate kinase, with two E-P intermediates and three steric inversions on phosphorus . It follows that a second E-P for acetate kinase must exist. Proc Natl Acad Sci U S A, 1980 May, 77(5), 2514 - 8 Fate of donor insertion sequence IS1 during transposition; Read HA et al.; The number of insertion sequence IS1 segments in Escherichia coli K-12 and 20 mutants in which an ISI had been inserted at a new site was measured by Southern blot hybridization analysis . The parent strain appeared to contain seven IS1 segments . Each of the mutants contained these seven IS1 and one additional IS1 corresponding to the new IS1 insertion . These results suggest that a copy of a donor ISI is inserted at the new site . A model for transposition is prevented that postulates that a reactive intermediate is formed by a tandem duplication of a transposable sequence. J Biochem (Tokyo), 1980 May, 87(5), 1449 - 55 Comparative studies on alveolar macrophages and polymorphonuclear leukocytes . I . H2O2 and O2- generation by rabbit alveolar macrophages; Yamaguchi T et al.; The oxidative metabolism of rabbit alveolar macrophages (A-MO) was compared with that of rabbit polymorphonuclear leukocytes (PMN) with respect to H2O2 generation by intact cells or subcellular fractions . Rabbit PMN exhibited an increase in the oxygen uptake and a marked release of H2O2 upon addition of heat-killed E . coli in the presence and absence of opsonin . However, rabbit A-MO exhibited an increase in the oxygen uptake upon addition of E . coli only in the presence of anti-E . coli serum as an opsonin, whereas a very small amount of H2O2 release was observed during ingestion of the opsonized E . coli . The generation of O2- and H2O2 by a granule-rich fraction isolated from phagocytosing PMN was larger than that by a similar fraction isolated from resting PMN . However, there was no significant difference in O2- and H2O2 generation by the granule fractions between phagocytosing and resting A-MO in the presence of either NADH or NADPH . In contrast to the granule fraction of rabbit PMN, the O2- and H2O2 generating activities in the A-MO granule fraction were higher in the presence of NADH than in the presence of NADPH . The rates of NADH and NADPH oxidation by both A-MO and PMN granule fractions were measured with and without addition of Mn2+ to the assay medium . The effect of Mn2+ on the NAD(P)H oxidase was found to differ between rabbit A-MO and PMN. Gene, 1980 May, 9(3-4), 307 - 19 Cloning DNA restriction endonuclease fragments with protruding single-stranded ends; Wartell RM et al.; A new method of in vitro recombination was employed to construct plasmids containing lac promoter fragments 64 bp and 144 bp long . The 64 bp HpaII-HhaI fragment contains the binding site for the catabolite activator protein (CAP) . The HpaII-HaeIII 144 bp fragment includes the binding sites for RNA polymerase, the lac repressor and CAP . The method utilizes the ability of T4 DNA polymerase to make flush-ended DNA either by filling in a recessed 3'-end or by exonucleolytic removal of a protruding 3'-end . The treated fragments were then blunt-end ligated to the filled-in EcoRI cloning sites of the plasmids pVH51 and pBR322 using T4 ligase . In this process, the EcoRI sites were regenerated on the fragment ends thus facilitating the subsequent isolation of the fragments from their cloning vectors. Gene, 1980 May, 9(3-4), 287 - 305 Construction and characterization of new cloning vehicles . IV . Deletion derivatives of pBR322 and pBR325; Soberon X et al.; In vitro recombinant DNA experiments involving restriction endonuclease fragments derived from the plasmids pBR322 and pBR325 resulted in the construction of two new cloning vehicles . One of these plasmids, designated pBR327, was obtained after an EcoRII partial digestion of pBR322 . The plasmid pBR327 confers resistance to tetracycline and ampicillin, contains 3273 base pairs (bp) and therefore is 1089 bp smaller than pBR322 . The other newly constructed vector, which has been designated pBR328, confers resistance to chloramphenicol as well as the two former antibiotics . This plasmid contains unique HindIII, BamHI and SalI sites in the tetracycline resistance gene, unique PvuI and PstI sites in the ampicillin resistance gene and unique EcoRI, PvuII and BalI sites in the chloramphenicol resistance gene . The pBR328 plasmid contains approx . 4900 bp. Gene, 1980 May, 9(3-4), 213 - 31 The recognition site of type II restriction enzyme BglI is interrupted; Lautenberger JA et al.; The Type II restriction endonuclease BglI recognizes the interrupted DNA sequence 5'-G-C-C-N-N-N-N-N-G-G-C- . This sequence occurs at all locations in over 33 000 base pairs of DNA sequence where the enzyme was found to cut DNA and nowhere else . All six of the specified bases are essential parts of the site since all groups of five of the six bases occur in the DNA sequences tested and none of them are cut by BglI . The length of the block of intervening unspecified positions must be exactly five since all other sizes between zero and 15 occur in the DNA sequences searched and none are cut by BglI . The 5'-terminal nucleotides of BglI cleaved phage G4 replicative form DNA and plasmid pER18 DNA were compared with the DNA sequences near the BglI sites on these DNAs . These results indicated that BglI cuts within the intervening unspecified region and produces single-stranded 3' termini that are three bases long . The BglI recognition site and cleavage points can thus be represented as follows: (Formula: see text) . This study of the BglI recognition site was facilitated by the use of inexpensive microcomputers . A system of programs was developed that allowed analysis of over 33 kb of DNA sequences stored on flexible magnetic disks or audio cassettes . While these programs were generally written in the higher level language BASIC, some assembly language subroutines were utilized to reduce execution time. Gene, 1980 May, 9(3-4), 205 - 12 The DNA sequence recognised by BglI; Bickle TA et al.; The restriction enzyme BglI recognizes the DNA sequence: (Formula: see text) and cleaves it in the position shown by the arrows to leave 3' single-stranded protrusions three bases long. Cell, 1980 May, 20(1), 245 - 54 Formation and resolution of DNA catenanes by DNA gyrase; Kreuzer KN et al.; We have discovered that DNA gyrase interlocks duplex DNA circles to form catenanes and resolves catenanes into component monomers . The reactions were inhibited by novobiocin and oxolinic acid and required ATP, Mg++ and spermidine . DNA sequence homology is not involved in catenation, since hybrid catenanes were formed efficiently between supercoiled phi X174 and Col E1 DNA . Strikingly different results were obtained with native and relaxed Col E1 DNA substrates . Up to 50-60% of input native DNA was converted into oligomeric catenanes, predominantly dimers and trimers . Relaxed substrates were instead converted into vast interlocked networks and were occasionally knotted . Optimal catenation occurred only in the narrow range of 20-35 mM KCl; increased ionic strength blocked catenation completely but activated the back reaction of decatenation . Gyrase resolved both the oligomeric catenanes and interlocked networks it produced, as well as naturally occurring catenanes . These results imply that the mechanism of gyrase involves a transient double-strand break and passage of a DNA segment through the resulting gap . Gyrase is representative of a general class of enzymes, found in both procaryotic and eucaryotic cells, that facilitate diffusion of duplex DNA segments through each other and may thereby solve topological problems arising from the replication, recombination and condensation of DNA. J Bacteriol, 1980 May, 142(2), 701 - 13 Transposon-mediated conjugational transmission of nonconjugative plasmids; Crisona NJ et al.; When coresident with conjugative plasmid pNC21, the nonconjugative deletion F-prime pJC59, which retains the F transfer origin oriT, was transmitted to transconjugants at a frequency comparable to that of pNC21 . In addition, pJC59 was transmitted as an independent plasmid, physically separate from pNC21, an example of plasmid donation . In contrast, two plasmids that are derived from F and deleted for the oriT site, pJC61 and pML31, were transmitted at frequencies 10(4) lower than that of pNC21 . This low-frequency transmission was associated with the appearance of a new plasmid in the transconjugants . In the case of pML31, we determined that this new plasmid was a recombinant composed of pNC21 and pML31, the latter flanked by two copies of transposable element Tn3 . We believe that this recombinant plasmid was formed as an intermediate in the transposition of Tn3 from pNC21 to pML31 and was the vehicle for conjugational transmission of pML31 genes by a process known as plasmid conduction. J Bacteriol, 1980 May, 142(2), 659 - 67 Deoxyribonucleic acid sequence of araBAD promoter mutants of Escherichia coli; Horwitz AH et al.; The controlling site region for the araBAD operon is defined, in part, by two classes of cis-acting constitutive mutations . The aralc mutations allow low-level constitutive expression of ara-BAD in the absence of the positive regulatory protein coded for by the araC gene, whereas the araXc mutations allow expression of araBAD in the absence of the cyclic adenosine monophosphate receptor protein . Six independently isolated aralc mutations and three independently isolated araXc mutations were cloned onto the plasmid pBR322 using in vitro recombinant deoxyribonucleic acid techniques and in vivo recombination between plasmid and chromosomal deoxyribonucleic acid . The location of these mutations was determined by deoxyribonucleic acid sequence analysis . All of the aralc mutations occurred at position -35 within the araBAD promoter (+1 = messenger ribonucleic acid start for araBAD) and resulted from an AT leads to GC transition . All of the araXc mutations occurred at position -10 within the araBAD promoter and resulted from a GC leads to AT transition . Models are presented to explain the mode of action of the aralc and araXc mutations. J Bacteriol, 1980 May, 142(2), 621 - 32 Regulation of fatty acid degradation in Escherichia coli: isolation and characterization of strains bearing insertion and temperature-sensitive mutations in gene fadR; Simons RW et al.; Transposon Tn10 was used to mutagenize the fadR gene in Escherichia coli . Mutants bearing fadR:Tn10 insertion mutations were found to (i) utilize the noninducing fatty acid decanoate as sole carbon source, (ii) beta-oxidize fatty acids at constitutive rates, and (iii) contain constitutive levels of the five key beta-oxidative enzymes . These characteristics were identical to those observed in spontaneous fadR mutants . The constitutive phenotype presented by the fadR:Tn10 mutants was shown to be genetically linked to the associated transposon-encoded drug resistance . These results suggest that the fadR gene product exerts negative control over the fatty acid degradative regulon . The fadR gene of E . coli has been mapped through the use of transposon-mediated fadR insertion mutations . The fadR locus is at 25.5 min on the revised map and cotransduces with purB, hemA, and trp . Three-factor conjugational and transductional crosses indicate that the order of loci in this region of the chromosome is purB-fadR-hemA-trp . Spontaneous fadR mutants were found to map at the same location . Strains that exhibit alterations in the control of the fad regulon in response to changes in temperature were also isolated and characterized . These fadR(Ts) mutants were constitutive for the fad enzymes at elevated temperatures and inducible for these activities at low temperatures . The fadR(Ts) mutations also map at the fadR locus . These results strongly suggest that the fadR gene product is a repressor protein. J Bacteriol, 1980 May, 142(2), 556 - 67 Location of the multivalent control site for the ilvEDA operon of Escherichia coli; Gayda DJ et al.; A strain of Escherichia coli K-12 containing a deletion extending from early in the ilvE gene toward the ilvG gene was shown to exhibit a higher expression of the downstream genes, ilvD and ilvA, than did an ilv+ strain . The elevated expression was under apparently normal ilv-specific control, however . The deletion was transferred to the ilv region of lamba h80dilv and shown by restriction endonuclease and heteroduplex analysis to extend through the deoxyribonucleic acid (DNA) shown, in the preceding paper (C . S . Subrahmanyam, G . M . McCorkle, and H . E . Umbarget, J . Bacteriol 142:547--555, 1980), to contain the ilvO determinant . The deletion was also transferred to an ilv-lac fusion strain and shown to cause an increase in beta-galactosidase formation while allowing retention of ilv-specific control . Transducing phages excised from these fusion strains with and without the ilvO determinant were compared . The phage carrying the ilvO+ determinant contained ilv DNA extending only into but not through the ilvG gene . It did not exhibit an ilv-specific control of beta-galactosidase formation . The phage carrying the deletion of ilvO but containing ilv DNA extending beyond the ilvG gene exhibited ilv-specific control of beta-galactosidase formation . It was concluded that the multivalently controlled ilv-specific promoter affecting ilv operon expression lies upstream from ilvG and that the ilvO region in the wild-type K-12 strain is a region of polarity preventing ilvG expression and reducing ilvEDA expression. J Bacteriol, 1980 May, 142(2), 371 - 9 Cloning and restriction mapping of the trmA gene coding for transfer ribonucleic acid (5-methyluridine)-methyltransferase in Escherichia coli K-12; Ny T et al.; A hybrid plasmid from the Clarke and Carbon collection has been isolated . This plasmid carries the trmA gene of E . coli, which is necessary for the formation of 5-methyluridine (m5U,ribothymidine) present in all transfer ribonucleic acid (tRNA) chains of the organism so far sequenced . A restriction map of the argCBH-trmA regions is presented . By using cloning in vitro, the trmA gene was located on a 2.9-kilobase pair deoxyribonucleic acid (DNA) fragment . These results and comparison with lambda dargECBH transducing phages established the gene order: argECBH trmA bfe in the 88-min region of the E . coli chromosomal map . Plasmids carrying this 2.9-kilobase pair DNA fragment overproduce the enzyme tRNA(m5U)methyltransferase (EC 2.1.1.35) 20 to 40 times . When this 2.9-kilobase pair chromosomal DNA fragment was expressed in a minicell system, a polypeptide of a molecular weight of 42,000 was synthesized . This polypeptide was tentatively identified as the tRNA(m5U)methyltransferase . These results support the earlier suggestion that the trmA gene is the structural gene for the tRNA(m5U)methyltransferase. J Lab Clin Med, 1980 May, 95(5), 654 - 9 Stimulation of cyclic 3':5'-guanosine monophosphate levels in rat spleen cells by lipopolysaccharide preparations; Bomboy JD Jr et al.; LPS greatly increases cGMP in rat fetal liver cells without affecting cAMP . The present experiments were undertaken to determine whether this effect occurs in an adult tissue, which might be exposed to LPS in vivo . Therefore cyclic nucleotides were measured in adult male rat spleen cells incubated in vitro in the presence or absence of LPS . A clear cGMP elevation was found in cultures treated with LPS . This was first evident at 2 hr and persisted for 4 hr . In contrast, cAMP was unaffected by LPS even in the presence of the phosphodiesterase inhibitor, MIX . CGMP rose progressively with LPS doses ranging from 0.8 to 20 ng, and addition of MIX potentiated the cGMP stimulatory effect . Several LPS concentrates prepared by different techniques and LPS exposed to vigorous heat treatment exhibited cGMP activity, whereas absorption of LPS with Limulus lysate abolished the cGMP response . Thus LPS increases cGMP in rat spleen cells in a dose-and time-dependent manner without affecting cAMP . Although the significance of this cGMP increase is unknown, its occurrence in spleen cells (a tissue likely to come in contact with LPS in vivo), its production by very small quantities of LPS, and the delayed but persistent nature of the effect (analogous to the aciton of cholera toxin on cAMP) are all consistent with an important role for cGMP in the action of LPS on cells. Eur J Biochem, 1980 May, 106(1), 321 - 8 Purification and characterization of a mutant tRNA nucleotidyltransferase; McGann RG et al.; tRNA nucleotidyltransferase has been extensively purified from a mutant strain of Escherichia coli which displays greatly decreased AMP incorporation, but normal CMP incorporation . The defect in AMP incorporation is retained throughout the purification of the mutant protein . The mutant protein behaves identically to the wild-type protein with regard to elution position on various chromatographic columns, and both have similar molecular weights of about 50000 . The defect in the mutant protein is accentuated by the use of yeast tRNA rather than E . coli tRNA-C--C as substrate, by decreased pH, by increased ionic strength and by decreased divalent cation concentration . Substitution of MN2+ for Mg2+ greatly increases the relative activity of the mutant enzyme . In all these cases, CMP incorporation by the mutant enzyme remains the same as the wild-type enzyme . The Km values of the mutant enzyme for its tRNA and triphosphate substrates are unchanged, and the mutant protein is as stable as the wild type with respect to temperature inactivation . These results strongly suggest that the mutation is in the structural gene for tRNA nucleotidyltransferase, and that the mutation probably does not affect the overall structure of the mutant protein, but only a localized region near the AMP-incorporating site. Can J Microbiol, 1980 May, 26(5), 636 - 9 The effect of trans-{Rh(4-ethylpyridine)4Cl2}Cl x 2H2O on nucleic acid and protein syntheses in Escherichia coli; Seeman SL et al.; The effect of the transition metal compound trans-{Rh(4-ethylpyridine)4Cl2}Cl x 2H2O on the syntheses of DNA, RNA, and protein has been investigated for an auxotrophic bacterial strain, Escherichia coli JS-1, incapable of thymidine, uridine, and histidine syntheses . At low concentration (7.4 x 10(-6) M), this rhodium complex interferes with normal cell division and induces the formation of filaments comparable to those observed in the presence of the cis-(NH3)2PtClx antitumour agents . Once the suppressed growth rate of the filamenting cells has been taken into account, the rhodium compound is found not to alter macromolecular synthesis . Again this is consistent with similar observations made for the platinum compounds. J Bacteriol, 1980 May, 142(2), 547 - 55 Physical location of the ilvO determinant in Escherichia coli K-12 deoxyribonucleic acid; Subrahmanyam CS et al.; A plasmid carrying the 4,6-kilobase (kb) HindIII-derived fragment from an ilvO mutant derivative of lambda h80dilv imparted a valine-resistant phenotype on strains it carried . This fragment carries a small amount of the promoter-proximal end of ilvE, the ilvO determinant, and apparently the entire ilvG gene, which specifies the valine-insensitive acetohydroxy acid synthase . Comparable deoxyribonucleic acid (DNA) from the original lambda h80dilv did not carry the valine resistance marker . The valine-resistant phenotype was always correlated with the formation of the resistant enzymes . The ilvO determinant was shown to be carried within an approximately 600-based-pair region lying between the SalI and KpnI sites on the HindIII fragment and perhaps within the ilvG gene itself . Ribonucleic acid that hybridizes with the DNA corresponding to the ilvG gene is formed in wild-type K-12 cells . This fact, coupled with the fact that ilvG is transcribed from the same DNA strand as the ilvE, D, and A genes, led to the idea that transcription is normally initiated upstream from ilvG in both wild-type and ilvO strains . In wild-type strains either the formation or the translation of the transcript would be terminated with the ilvG gene, thus preventing expression of that gene. J Bacteriol, 1980 May, 142(2), 384 - 90 Mutations which affect the structure and activity of colicin E3; Mock M et al.; Among 69 ColE3 mutant plasmids selected on the basis of their inability to produce an active colicin, seven (cop-1 to cop-7) were found to bear a mutation affecting the structural gene for colicin . Three of these (cop-1, cop-2 and cop-3) lead to the production of an inactive colicin molecule which has the same molecular weight as wild-type colicin E3 (67,000) . These three inactive colicins are still able to interact with the outer membrane receptor . The cop-1 protein retained the ability to inhibit protein synthesis in vitro and therefore seems specifically affected in it ability to penetrate the cell envelope . The cop-2 and cop-3 proteins lost the ability to inhibit protein synthesis in vitro, and activity which is normally associated with the C-terminal part of the colicin molecule . On the basis of this and further evidence, it is suggested that the cop-2 and cop-3 mutations affect the structure of the C-terminal part of the colicin molecule . The other four mutations (cop-4 to cop-7) lead to the production of colicin-related polypeptides of lower molecular weight (29,000 to 45,000) which display a reaction of partial immunological identity with wild-type colicin . These four polypeptides are unable to interact with the cell surface receptor . Three of these mutants are shown to carry a nonsense mutation. Gene, 1980 May, 9(3-4), 321 - 36 Cloning of the dut (deoxyuridine triphosphatase) gene of Escherichia coli; Taylor AF et al.; Through the molecular cloning of DNA, cells were obtained that could produce a 300-fold increased level of deoxyuridine triphosphatase (dUTPase) . First, lambda pyrE-dut phages were constructed from restriction endonuclease fragments . They contained a segment of Escherichia coli DNA that spanned the structural genes for dUTPase (dut) and orotidylate pyrophosphorylase (pyrE) . The initial isolates demonstrated poor enzyme production and impaired growth . Improved enzyme yields were then obtained from large-plaque derivatives and from mutants with partial deletions of the cloned DNA . The deletion mutants were isolated after the induction of a recombinant prophage whose DNA was too large to be packaged . Finally, a 3.3-kb segment of DNA, containing the dut gene, was transferred to plasmid vectors . The recombinants and their levels of dUTPase overproduction (relative to that of wild type cells) were as follows: a thermoinducible lambda pyrE-dut phage, 45-fold (10-fold for orotidylate pyrophosphorylase); a dut-ColE1 type plasmid, 15-fold; and a thermoinducible dut-lambda-ColE1 chimera, 14-fold before induction and 300-fold after induction. Biochim Biophys Acta, 1980 Apr 30, 607(2), 247 - 55 Mechanism of the ATP effect in the DNA repair synthesis of gamma-irradiated Escherichia coli cells; Gartner C et al.; Gamma-irradiation of Escherichia coli cells made permeable to deoxynucleoside triphosphates (dNTP) by toluene induces a repair-type DNA synthesis . As previous studies have shown ATP stimulates this DNA synthesis; we studied the mechanism of the ATP effect by analyzing the kinetics of nucleotide incorporation at various dNTP concentrations . The V values of the DNA repair synthesis rise with increasing dose (0-50 Gy); nonirradiated cells showed a negligible nucleotide incorporation . The apparent Michaelis constant KM for dNTP in the assay was 83-143 microM and the value was much higher than for a DNA polymerase reaction in vitro . ATP stimulated the DNA synthesis with concomitant decrease of KM yet unchanged V values . Similar results were obtained with a rec BC strain . We propose that the ATP effect is due to a greater affinity of dNTPs to the DNA polymerase, possibly by a stabilisation of the structural integrity of the complex DNA with repair enzymes . Activation of exonucleases by ATP could be excluded . Addition of NAD to the reaction mixture inhibits the DNA synthesis possibly by activation of ligase which closes the nicks in the DNA strand. Biochim Biophys Acta, 1980 Apr 30, 607(2), 277 - 84 Non-coordinate regulation of enzymes involved in transfer RNA metabolism in Escherichia coli; Ny T et al.; During different steady state growth conditions in Escherichia coli the level of the three tRNA-modifying enzymes, the tRNA(m5Urd)-, tRNA(m1Guo)- and tRNA(mam5s2Urd)methyltransferase and of five aminoacyl-tRNA synthetases, the leucyl-, valyl-, isoleucyl-, arginyl- and threonyl-tRNA-synthetase, has been determined . It is shown that those two classes of tRNA affecting enzymes are not coordinately regulated and that even within these two groups of enzymes the constituents are regulated independently of each other . Furthermore it is demonstrated that none of the aminoacyl-tRNA synthetases and only one of the three tRNA-methyltransferases, the tRNA(m5Urd)methyltransferase, is under control of the relA+-gene. Biochemistry, 1980 Apr 29, 19(9), 1857 - 61 Photoaffinity labeling of the adenosine cyclic 3',5'-monophosphate receptor protein of Escherichia coli with 8-azidoadenosine 3',5'-monophosphate; Aiba H et al.; Photoaffinity labeling of the cAMP receptor protein (CRP) of Escherichia coli with 8-azidoadenosine 3',5'-monophosphate (8-N3cAMP) has been demonstrated . 8-N3cAMP is able to support the binding of (3H)d(I-C)n by CRP, indicating that it is a functional cAMP analogue . Following irradiation at 254 nm, (32P)-8-N3cAMP is photocross-linked to CRP . Photolabeling of CRP by (32P)-8-N3cAMP is inhibited by cAMP but not by 5'AMP . The data indicate that (32P)-8-N3cAMP is covalently incorporated following binding at the cAMP binding site of CRP . The (32P)-8-N3cAMP-CRP digested with chymotrypsin was analyzed by NaDodSO4-polyacrylamide gel electrophoresis . Of the incorporated label, one-third remains associated with the amino-proximal alpha core region of CRP {Eilen, E., Pampeno, C., & Krakow, J.S . (1978) Biochemistry 17, 2469} which contains the cAMP binding domain; the remaining two-thirds of the label associated with the beta region are digested . Limited proteolysis of the (32P)-8-N3cAMP-CRP by chymotrypsin in the presence of NaDodSO4 shows the radioactivity to be distributed between the molecular weight 9500 (amino-proximal) and 13,000 (carboxyl-proximal) fragments produced . These results suggest that a part of the carboxyl-proximal region is folded over and close enough to the cAMP binding site to be cross-linked by the photoactivated (32P)-8-N3cAMP bound at the cAMP binding site. J Biol Chem, 1980 Apr 25, 255(8), 3707 - 12 Accumulation of glyceride-containing precursor of the outer membrane lipoprotein in the cytoplasmic membrane of Escherichia coli treated with globomycin; Hussain M et al.; The protein accumulated in the cell envelope of Escherichia coli treated with globomycin was identified as the precursor of the outer membrane lipoprotein . The prolipoprotein was almost exclusively localized in the cytoplasmic membrane . The prolipoprotein could be immunoprecipitated with antilipoprotein immunoglobulin and could be chased to the lipoprotein in both in vivo and in vitro . Globomycin inhibited the chase . The prolipoprotein contained glycerol and fatty acid residues, whereas no free sulfhydryl group was detected in it . From these results, it is concluded that the prolipoprotein possesses a glyceride which is covalently bound to the cysteine residue in the peptide as the lipoprotein does and that the removal of signal peptide takes place after the modification . The inhibition of bacterial growth with increasing concentrations of globomycin was accompanied by a gradual increase in the accumulation of the prolipoprotein . Furthermore, growth of the lipoprotein-negative mutant was highly resistant to globomycin . These results strongly indicate that the accumulation of the prolipoprotein in the cytoplasmic membrane causes the death of cells. J Biol Chem, 1980 Apr 25, 255(8), 3536 - 41 Regulation of RNA polymerase synthesis . Conditional lethal amber mutations in the beta subunit gene; Little R et al.; Amber mutations in the rpoB gene specifying the beta subunit of RNA polymerase coupled with conditional amber suppressors were used to restrict the synthesis of core RNA polymerase in strains of Escherichia coli . Such a restriction stimulated transcription of genetic units containing RNA polymerase subunit genes . Within the L10 transcription unit (genetic structure: promotor (PL10), rplJ (L10), rplL (L7/L12), attenuator, rpoB (beta), rpoC (beta'), terminator), the initiation of transcription at the promotor was enhanced and termination at the transcription attenuator was relaxed . Transcription of the genetic unit containing the rpoA gene (alpha) was also enhanced . In the strain containing a non-polar amber mutation, the synthesis rate of the beta' subunit protein during the restriction correlated with the level of transcription of the beta and beta' genes . In contrast, synthesis of L7/L12 ribosomal protein remained essentially unaltered in spite of the elevated levels of L10-L7/L12 mRNA. J Biol Chem, 1980 Apr 25, 255(8), 3263 - 5 Beta-ketoacyl-acyl carrier protein synthase II of Escherichia coli . Evidence for function in the thermal regulation of fatty acid synthesis; Garwin JL et al.; Cvc- mutants of Escherichia coli are deficient in the synthesis of cis-vaccenic acid and in the temperature control of fatty acid synthesis . In this communication, it is demonstrated that these mutants lack beta-ketoacyl-acyl carrier protein synthase II . The deficiencies in cis-vaccenate synthesis and synthase II are shown to be due to a lesion in the same gene, fabF . Lesions in the fabF gene are found to affect growth only when the strain also carries a lesion in the fabB gene, the structural gene for beta-ketoacyl-acyl carrier protein synthase I. J Biol Chem, 1980 Apr 25, 255(8), 3227 - 9 Sulfhydryl groups of Escherichia coli ribosomal protein S1 . Location along the polypeptide chain; Subramanian AR; The location of the functionally important -SH groups of Escherichia coli ribosomal protein S1 along the polypeptide chain has been determined using a cysteine-specific cleavage procedure . The two -SH groups of S1 are located at 57% and 67% of the polypeptide chain length from the NH2 terminus . The -SH group farther from the NH2 terminus is shown to be the more reactive one . Two truncated derivatives of S1 (S1-F1 and m1-S1) both contain two -SH groups . It has previously been shown that S1-F1 (which lacks the NH2-terminal region of S1) is inactive in unfolding nucleic acids, just as the N-ethylmaleimide derivative of S1 . The present results therefore show that the formation and functioning of the nucleic acid unfolding domain of protein S1 requires the -SH group(s) as well as the NH2-terminal region. Nucleic Acids Res, 1980 Apr 25, 8(8), 1873 - 91 Precursors to 16S and 23S ribosomal RNA from a ribonuclear III-strain of Escherichia coli contain intact RNase III processing sites; Gegenheimer P et al.; Escherichia coli cells lacking the ribosomal RNA processing enzyme RNase III do no excise the normal RNA precursors p16a (17S) and p23a from nascent rRNA transcripts . These cells produce, instead, slightly larger p16b and p23b precursors . Digestion of p16b or p23b rRNA with RNases A plus T1 yields double-stranded fragments composed of sequences, located at both the 5' and the 3' end regions of the molecules . The terminal duplex, or stem, of p16b contains sequences surrounding the site of RNase III processing which is wild-type cells produces p16a rRNA: the p23b stem likewise contains an intact RNase III cleavage site . The results confirm our earlier prediction for the structure of rRNA transcripts, and also yield a definite secondary structure for the p16 stem, which was not uniquely determined by the corresponding DNA sequence . These experiments demonstrate the absence of significant RNase III processing activity in rnc-105 strains of E . coli, and implicate the participation of another endonuclease(s) in rRNA processing in mutant and wild-type cells. Nucleic Acids Res, 1980 Apr 25, 8(8), 1693 - 707 Two rearranged immunoglobulin kappa light chain genes in one mouse myeloma; Steinmetz M et al.; The organization of immunoglobulin gene segments coding for kappa light chains has been studied in uncloned and cloned DNA from mouse liver and a mouse myeloma . It is known that the C (constant, ref . 2) gene segment is present in the tumor DNA on two EcoRI fragments of 14 and 20 kb and in liver DNA on a 15 kb fragment . The 14 kb myeloma and the 15 kb liver fragment have been cloned previously . Here we report on the cloning of the 20 kb myeloma fragment and present detailed restriction maps covering about 22 kb of DNA surrounding the C gene segment in liver and tumor DNA . The region on the 20 kb fragment has been localized where a DNA rearrangement had occurred . The presence of two rearranged kappa light chain genes in one tumor is discussed in regard to the molecular basis of allelic exclusion. J Biol Chem, 1980 Apr 25, 255(8), 3726 - 35 The effect of divalent cations on the mode of action of DNase I . The initial reaction products produced from covalently closed circular DNA; Campbell VW et al.; The effect of different divalent metal ions on the hydrolysis of DNA by DNase I was studied with an assay which distinguishes between cleavage of one or both strands of the DNA substrate during initial encounters between enzyme and DNA . Using covalently closed superhelical SV40(I) DNA as substrate, initial reaction products consisting of relaxed circles or unit-length linears are resolved by electrophoresis of radioactively labeled DNA in agarose gels . Only in the presence of a transition metal ion, such as Mn2+ or Co2+, and only under certain reaction conditions, is DNase I able to cut both DNA strands at or near the same point, generating unit-length linears . This ability to cut both DNA strands is inhibited by such factors as temperature decrease, the addition of a monovalent ion or another divalent cation which is not a transition metal ion, or a reduction in the number of superhelical turns in the DNA substrate . All of these factors lead to a winding of the duplex helix and antagonize the unwinding of the duplex promoted by transition metal ion binding . Transition metal ions may thus convert the DNA substrate locally to a form in which DNase I can introduce breaks into both strands . In the presence of Mg2+, DNase I introduces single strand nicks into SV40(I), generating exclusively the covalently open, relaxed circular SV40(II) as the initial product of the reaction . In the presence of Mn2+, DNase I generates as initial products a mixture of SV40(II) and unit-length SV40 linear DNA molecules, formed by two nicks in opposite strands at or near the same point in the duplex . These circular SV40(II) molecules consist of two types . A minority class is indistinguishable from the nicked SV40(II) produced by DNase I in the presence of Mg2+ . The majority class consists of molecules containing a gap in one of the two strands, the mean length of the gap being 11 nucleotides . The SV40(L) molecules produced in the presence of Mn2+ appear to have single strand extensions at one or both ends. J Biol Chem, 1980 Apr 25, 255(8), 3581 - 4 Actinomycin D binds with highest affinity to nonribosomal DNA; Khan MM et al.; Based on previous evidence (T.J . Lindell (1976) Nature 263, 347-350 and T.J . Lindell, A.F . O'Malley, and B . Puglisi (1978) Biochemistry 17, 1154-1160) it was anticipated that actinomycin D in a low concentration would bind to DNA which is involved in the regulation of rRNA transcription in eukaryotes . This was examined by digestion of rat (liver) DNA with EcoRI, adding {3H}actinomycin D (0.004 microgram/ml) and resolution of the restriction fragments by RPC-5 chromatography . Labeled actinomycin D was found to bind with highest affinity to a single fraction consistently eluting at 0.63 M KCl . A similar digestion and fractionation of nucleolar DNA, which is enriched in rDNA sequences, did not reveal a similar high affinity binding of actinomycin D . This fraction of DNA which binds actinomycin D with highest affinity did not contain any rDNA as evidenced by hybridization with {32P}rRNA . Therefore, at the concentration of 0.004 microgram/ml, actinomycin D does not selectively bind to rDNA as evidenced by two independent criteria . Whether this high affinity actinomycin D-binding DNA has any function in the regulation of rRNA transcription remains to be determined. Biochim Biophys Acta, 1980 Apr 24, 597(3), 502 - 17 31P nuclear magnetic resonance and freeze-fracture electron microscopy studies on Escherichia coli . II . Lipopolysaccharide and lipopolysaccharide-phospholipid complexes; van Alphen L et al.; 1 . Freeze-fracture electron microscopy and 31P-NMR spectroscopy on native and electrodialyzed lipopolysaccharide from Escherichia coli K12 cells, both above and below the phase transition temperature, are described . 2 . Freeze-fracture electron microscopy of native lipopolysaccharide shows ribbon-like structures below (0 and 22 degrees C) and large vesicles above (37 degrees C) the phase transition temperature . Electrodialyzed lipopolysaccharide (sodium salt) occurs in ribbon-like structures at 0, 22 and 37 degrees C if sodium lipopolysaccharide is hydrated in water . If sodium lipopolysaccharide is hydrated in Tris-HCL/NaCl buffer these ribbon-like structures occur only below the phase transition temperature . Above the phase transition temperature stacked sheets are observed . Moreover, in the latter case, the fracture planes contain particles and pits . Upon etching, sodium lipopolysaccharide when hydrated in water appears to form rods and when hydrated in buffer appears to form mainly stacked lamellae both above (37 degrees C) and below (0 degrees C) the phase transition temperature . 3 . High resolution 31P-NMR spectra show that the chemical shifts of the phosphorus atoms in native lipopolysaccharide differ from those in electrodialyzed lipopolysaccharide, probably due to conformational and compositional (the disappearance of ions and (poly)electrolytes) changes . The 31P-NMR spectra of native lipopolysaccharide dispersed in Tris-HCL/NaCl buffer are very broad at 20 and at 40 degrees C indicating little motion . At 22 degrees C electrodialyzed lipopolysaccharide also gives a broad spectrum; at 40 degrees C the spectrum is narrower, indicating more motion, and two peaks are visible . After dispersion in H2o and subsequent addition of buffer, the spectrum of electrodialyzed lipopolysaccharide is narrow both at 20 and 40 degrees C, which can be correlated with the rods observed in freeze etching . After treatment with Ca2+, electrodialyzed lipopolysaccharide shows a very broad spectrum at 40 degrees C probably due to immobilization of the lipopolysaccharide . 4 . Freeze-fracture electron microscopy and 31P-NMR spectroscopy of liposomes consisting of native lipopolysaccharide and total phospholipids indicate that the phospholipids and the lipopolysaccharide are mainly organized in bilayers . Lipopolysaccharide in such liposomes undergoes more motion than in the absence of phospholipids . Ca2+ does not influence this behaviour. Biochim Biophys Acta, 1980 Apr 24, 597(3), 492 - 501 31P nuclear magnetic resonance and freeze-fracture electron microscopy studies on Escherichia coli . I . Cytoplasmic membrane and total phospholipids; Burnell E et al.; 1 . At the growth temperature the total phospholipids isolated from Escherichia coli cells give rise to 31P-NMR spectra which indicate the existence of lamellar, isotropic and hexagonal phases . These phases are also detected by freeze fracture electron microscopy . In particular, the isotropic phase may contain lipidic particles (possibly inverted micelles) associated with the lamellar phase . 2 . The cytoplasmic membrane isolated from E . coli cells grown at 37 degrees C is mainly lamellar at 25 degrees C, whereas at 37 and 45 degrees C the presence of some almost isotropic phospholipid motion is indicated . The possible significance of the isotropic phase for the functioning of the cytoplasmic membrane is discussed. Biochim Biophys Acta, 1980 Apr 24, 597(3), 518 - 32 31P nuclear magnetic resonance and freeze-fracture electron microscopy studies on Escherichia coli . III . The outer membrane; Burnell E et al.; 1 . The outer membrane of a phospholipase A-deficient mutant of Escherichia coli K12, isolated without the use of EDTA and lysozyme, showed the same freeze-fracture morphology as that seen in cells and remained stable for hours as observed by 31P-NMR . 2 . 31P-NMR spectroscopy of the isolated outer membranes revealed that the lipopolysaccharide exists in the same physical state as in phospholipid-lipopolysaccharide liposomes and is most probably arranged in a bilayer at 37 degrees C . The outer membrane contains most or all of the phospholipids at 37 degrees C, and all the phospholipids at 20 degrees C, as a bilayer . 3 . The 31P-NMR spectroscopy of the outer membranes from a mutant strain lacking the major outer membrane protein b, c and d (60% of the total outer membrane protein) yields virtually the same spectrum as the wild-type outer membranes, although most of the particles and pits which were observed in wild-type outer membranes in freeze-fracture electron microscopy were absent . 4 . Whereas treatment of wild-type outer membranes with calcium ions has no effect on the 31P-NMR spectrum, treatment with EDTA results in more motion of the lipopolysaccharide. Biochemistry, 1980 Apr 15, 19(8), 1656 - 62 Functional heterogeneity of Escherichia coli ribonucleic acid polymerase holoenzyme; Travers AA et al.; On zone sedimentation Escherichia coli RNA polymerase holoenzyme exhibits functional heterogeneity with respect to template preference, regulation by ppGpp, and affinity for fMet-tRNA . The template preference of a subpopulation of RNA polymerase molecules correlates with both its sedimentation position and its ability to respond to effectors of polymerase selectivity . Incubation of such functionally distinct populations of enzyme molecules at physiological temperatures results in functional and structural equivalence . We suggest that RNA polymerase normally exists as a mixture of interconvertible forms and that promoter selection can be controlled by varying the number and proportions of forms present. Biochemistry, 1980 Apr 15, 19(8), 1651 - 6 Translation initiation factor 2 alters transcriptional selectivity of Escherichia coli ribonucleic acid polymerase; Travers AA et al.; Preparations of translation initiation factor IF-2 strongly stimulate the production of rRNA by Escherichia coli RNA polymerase but have little effect on the synthesis of other RNA species . The factor alters the sedimentation characteristics of RNA polymerase holoenzyme . We suggest a mechanism by which IF-2 alters the pattern of transcriptional selectivity of RNA polymerase. Am J Obstet Gynecol, 1980 Apr 15, 136(8), 976 - 9 Single-dose and multidose prophylaxis in vaginal hysterectomy: a comparison of sodium cephalothin and metronidazole; Hamod KA et al.; A total of 79 patients underwent vaginal hysterectomy and were randomly assigned to three regimens of prophylactic antibiotics: multidose intravenous sodium cephalothin, single-dose intravenous sodium cephalothin, and single-dose oral metronidazole . Control groups were selected from two previous studies conducted at our institution . The incidence rates of infectious morbidity following all three regimens of antibiotics were substantially lower than in the control groups . There was no statistically significant difference in the incidence of standard febrile morbidity and serious pelvic infections among the three groups . The fever index was lowest in the single-dose sodium cephalothin group. Nucleic Acids Res, 1980 Apr 11, 8(7), 1675 - 91 Azidopolynucleotides as photoaffinity reagents; Cartwright IL et al.; Polynucleotides containing adenosine and 8-azidoadenosine or inosine and 8-azidoinosine residues have been prepared from mixtures of nucleoside diphosphates using polynucleotide phosphorylase from Escherichia coli . These copolymers can form complexes with polyuridylic or polycytidylic acids respectively . Single stranded poly(adenylic, 8-azidoadenylic acid) {poly(A,z8A)} has been used as a photoaffinity reagent to explore the subunit topography of RNA polymerase from E . coli. Nucleic Acids Res, 1980 Apr 11, 8(7), 1561 - 73 Construction and characterization of a cDNA clone containing a portion of the bovine prolactin sequence; Nilson JH et al.; Poly(A)-containing RNA from the bovine anterior pituitary has been used as a template for the enzymatic synthesis of double-stranded cDNA . The resulting double-stranded cDNA was inserted into the Pst I site of pBR322 with the oligo(dG)-oligo(dC) tailing technique and subsequently cloned in E . coli chi 1776 . Clones containing sequences complementary to prolactin mRNA were identified by colony hybridization with partially purified prolactin cDNA . A 250 base pair sequence from one prolactin positive clone was extensively characterized and shown to contain the coding information for amino acids 119-192 of authentic bovine prolactin . The recombinant DNA from this clone was covalently attached to diazotized aminocellulose and used to purify prolactin mRNA from a mixture of mRNAs. Eur J Pharmacol, 1980 Apr 11, 63(1), 47 - 56 Blood levels of 6-oxo-prostaglandin F 1 alpha during endotoxin-induced hypotension in rabbits; Bult H et al.; Levels of 6-oxo-prostaglandin F1 alpha (6-oxo-PGF1 alpha), the non-enzymic degradation product of prostacyclin, were measured in arterial blood from anaesthetized rabbits, before and after intravenous (i.v.) administration of endotoxin (Lipopolysaccharine W E . coli 0111:B4, 5 mg/kg) . 6-Oxo-PGF1 alpha was assessed by radioimmunoassay after extraction and separation by thin-layer chromatography . The basal concentration of 6-oxo-PGF1 alpha in blood was less than 100 mg/ml in 19 out of 20 rabbits . This indicates that the level of circulating prostacyclin is generally below 100 pg/ml . The administration of endotoxin induced a biphasic hypotension, and increased levels of 6-oxo-PGF1 alpha were found in all endotoxin-treated animals during the secondary hypotension after 60 and 120 min . Pretreatment with indomethacin (2.5 mg/kg) prevented the secondary fall in arterial blood pressure and significantly suppressed the rise in 6-oxo-PGF1 alpha . However, indomethacin failed to alter the endotoxin-induced thrombocytopenia and did not modify the endotoxin-induced platelet aggregation in vitro . It is concluded that prostacyclin contributed to the secondary hypotension which accompanied the i.v . administration of endotoxin . Thromboxane A2 seems not to be of primary importance in the endotoxin-platelet interaction. Nucleic Acids Res, 1980 Apr 11, 8(7), 1445 - 57 Yeast mitochondrial methionine initiator tRNA: characterization and nucleotide sequence; Canaday J et al.; Two methionine tRNAs from yeast mitochondria have been purified . The mitochondrial initiator tRNA has been identified by formylation using a mitochondrial enzyme extract . E . coli transformylase however, does not formylate the yeast mitochondrial initiator tRNA . The sequence was determined using both 32P-in vivo labeled and 32P-end labeled mt tRNAf(Met) . This tRNA, unlike N . crassa mitochondrial tRNAf(Met), has two structural features typical of procaryotic initiator tRNAs: (i) it lacks a Watson-Crick base-pair at the end of the acceptor stem and (ii) has a T-psi-C-A sequence in loop IV . However, both yeast and N . crassa mitochondrial initiator tRNAs have a U11:A24 base-pair in the D-stem unlike procaryotic initiator tRNAs which have A11:U24 . Interestingly, both mitochondrial initiator tRNAs, as well as bean chloroplast tRNAf(Met), have only two G:C pairs next to the anticodon loop, unlike any other initiator tRNA whatever its origin . In terms of overall sequence homology, yeast mitochondrial tRNA(Met)f differs from both procaryotic or eucaryotic initiator tRNAs, showing the highest homology with N . crassa mitochondrial initiator tRNA. Nucleic Acids Res, 1980 Apr 11, 8(7), 1535 - 50 Structure of a promotor on plasmid pMB9 derived from plasmid pSC101; Pannekoek H et al.; The DNA sequence of a 354 basepair EcoRI-HindIII fragment of plasmid pMB9 which has originally been derived from plasmid pSC101 has been resolved . This fragment contains a promoter for transcription directed towards the EcoRI site . Escherichia coli RNA polymerase binds to a region within the EcoRI-HindIII fragment which contains the heptamer 5' TATGGTG (132-126) and the duodecamer 5' TGATGAACATCA (158-147) . Based on commonalities with other promotors these DNA sequences probably function as, respectively, "binding site" and "recognition site" . Furthermore, this fragment harbours a translation reading frame free of nonsense codons and at about 25 basepairs from the indicated heptamer a nucleotide sequence which meets with the requirements for initiation of translation . By heteroduplex mapping it was shown that the EcoRI-HindIII fragment has been derived from a region near or within the origin of replication of pSC101 . The copynumber of plasmids containing the EcoRI-HindIII fragment is two-fold lower than that of plasmids lacking this fragment . This effect might be related to the original function of this fragment on plasmid pSC101. Nucleic Acids Res, 1980 Apr 11, 8(7), 1505 - 19 Electron microscopic demonstration of the presence of amplified sequences at the 5'-ends of the polyoma virus late mRNAs; Zuckermann M et al.; Electron microscopic techniques were used to examine the structure of the leader sequences at the 5'-ends of the late polyoma virus mRNAs . The three late mRNA's were partially purified and hybridized to an E . coli plasmid containing two polyoma virus genomes inserted in tandem . The hybrids were spread by the cytochrome c-formamide technique and visualized in the electron microscope . These studies revealed that whereas the body of a given mRNA molecule can hybridize with only one of the two corresponding body sequences in the two adjacent viral genomes, the leader of the same mRNA molecule can hybridize with both copies of the leader sequence-specific DNA . The mVP1 and mVP3 RNA species thus generated hybrids containing two loops, while mVP2 molecules formed hybrids containing one loop . Hence, the leaders of the three polyoma virus late mRNA species must contain two or more repeats of a sequence transcribed from a unique DNA segment . Length measurements showed that most leaders in the late mRNA's consist of at least 200 nucleotides and some contain up to 500 nucleotides, whereas the basic repeat sequence contains about 60 nucleotides. Nucleic Acids Res, 1980 Apr 11, 8(7), 1459 - 73 The nucleotide sequence surrounding the replication origin of the cop3 mutant of the bacteriocinogenic plasmid Clo DF13; Stuitje AR et al.; The nucleotide sequence from about 100 base-pairs downstream to about 600 base pairs upstream the CloDF13 replication origin has been determined . A comparison of this sequence with the corresponding ColE1 origin sequence reveals that: The sequence at the origin of replication is conserved . There are large differences in the nucleotide sequence downstream the replication origin, whereas there is a large homology in the region of about 410 base-pairs upstream the replication origin . This conserved region might code for a largely homologous basic, arginine rich polypeptide of about 45 amino-acids, for both ColE1 and CloDF13 . Although there are large differences in the primary structure of the region coding for the 100 nucleotide RNA, the secondary structure of this region seems to be conserved. Biochim Biophys Acta, 1980 Apr 10, 597(2), 274 - 84 Measurements of membrane potentials in Escherichia coli K-12 inner membrane vesicles with the safranine method; Huttunen MT et al.; The use of safranine, a positively-charged dye, as a probe for the determination of membrane potentials in Escherichia coli vesicles has been studied . 1 . Shifts in the spectrum of safranine were observed during induction of potassium ion diffusion potentials with valinomycin or during oxidation of formate by vesicles prepared from cells of E . coli K-12 or ML 308-225 subjected to anaerobic growth with nitrate . The extent of the valinomycin-dependent spectral change correlated linearly with the magnitude of the K+ equilibrium potential, as calculated from the Nernst equation, from 50 to 160 mV (interior negative) . The formate-induced changes could also be calibrated by increasing the concentration of potassium in the presence of valinomycin, after the formation of formate-dependent responses . In this case, results identical to those obtained with the first method were obtained . 2 . O2 or nitrate-dependent oxidation of formate resulted in a membrane potential of the order of 170 mV . The oxidation of ascorbate-reduced N-methylphenazonium methosulphate resulted in a potential of similar magnitude, but anaerobically with nitrate only a small but definite potential was formed . 3 . The water-soluble quinones, duroquinone and menadione, could produce membrane potentials when used in their oxidized or reduced forms in the presence of formate or nitrate (or oxygen) . 2-Hydroxy-1,4-naphthoquinone was not only ineffective but was found to be inhibitory . 4 . N,N'-dicyclohexylcarbodiimide at suitable concentrations increased the rate of formation and the extent of membrane potentials induced by respiration or by artificial means. J Biol Chem . 1980 Apr 10;255(7):3042 8. The status of glycolaldehyde in the biosynthesis of vitamin B6; Vella GJ et al.; Competition experiments, employing 14C-labeled samples of glycerol and glycolaldehyde, indicate that in Escherichia coli B there are two independent pathways leading to pyridoxal . In mutant WG2 (and therefore presumably also in the wild strain) the major pathway utilizes glycerol and related trioses as the sole carbon source in the construction of the C8N skeleton of pyridoxol: C-1, -3 of glycerol yields C-2', -3, -4', -5' and -6, C-2 of glycerol yields C-2, -4, and -5 of the vitamin . In the minor pathway glycolaldehyde and not glycerol supplies C-5 and C-5' of pyridoxol, while glycerol is the source of the other 6 carbon atoms . In mutant WG3 the major route is blocked and the "glycolaldehyde pathway" becomes the sole source of vitamin B6. J Biol Chem, 1980 Apr 10, 255(7), 2897 - 901 A temperature-sensitive single-stranded DNA-binding protein from Escherichia coli; Meyer RR et al.; A temperature-sensitive single-stranded DNA-binding protein (SSB) has been purified from mutant Escherichia coli (ssb-1) cells by use of affinity chromatography on blue dextran-Sepharose . An altered amino acid sequence in the mutant protein is apparent in tryptic digests, confirming that the ssb mutation is in the structural gene . The mutant protein is less effective than the wild type in protecting single-stranded DNA from nuclease S1 digestion and in inhibiting DNA-dependent ATPases . The purified protein supports replication of phage G4 DNA in vitro at 30 degrees C, although higher levels of mutant protein, 4-fold higher than wild type, are needed to do so . The mutant protein becomes less active in supporting replication above 30 degrees C and becomes inactive at 42 degrees C within 1 min . Activity is restored upon return to 20 degrees C . Despite its temperature sensitivity in vivo and in vitro, the mutant binding protein can renature fully after exposure to 100 degrees C . Thus, the mutant protein is both heat-stable and functionally temperature-sensitive. J Biol Chem, 1980 Apr 10, 255(7), 2867 - 9 The use of 6-labeled glucose to assess futile cycling in Escherichia coli; Chambost JP et al.; To assess the "futile cycle" fructose-6-P leads to fructose-1,6-P2 leads to fructose-6-P in Escherichia coli we have grown the cells on {6-14C}glucose and determined label in the 1-position of glucose obtained from glycogen . In a variety of strains, including a wild type and a mutant without fructose diphosphatase, 1-position labeling was negligible . But there was little label in the 1-position of fructose-1,6-P2 either, which shows that hexose diphosphate and triose-P are not in equilibrium in this organism . Therefore, the lack of 1-position labeling in glycogen does not necessarily indicate lack of futile cycling . One strain, however, a temperature-sensitive glyceraldehyde-3-P dehydrogenase mutant grown at permissive temperature, gave substantial labeling of the 1-position of fructose-1,6-P2 . In this strain 1-position labeling in glycogen was low, indicating minimal futile cycling. J Biol Chem, 1980 Apr 10, 255(7), 2848 - 54 Dissociation and reconstitution of membranes synthesizing the peptidoglycan of Escherichia coli . Lipid dependence of the synthetic enzymes; Taku A et al.; The peptidoglycan synthetic enzymes can be dissociated with cholate and LiCl into components with mobilities on a gel filtration column in the same ranges as bovine serum albumin . The active enzymes can be separated further from the lipids necessary for synthesis by precipitation with ammonium sulfate . The needed lipids stable to hydrolysis with base . A protein needed for peptidoglycan polymerization can be separated from the other synthetic enzymes by hydroxylapatite chromatography. Lab Invest, 1980 Apr, 42(4), 450 - 6 Bone solubilization by mononuclear cells; McArthur W et al.; Mononuclear cells derived from chicken peripheral blood or from thioglycollate-induced mouse peritoneal exudates were found to cause calcium release from devitalized homologous bone in vitro . These mononuclear cells with osteolytic activity were adherent to plastic surfaces and were identified as being macrophages by cell surface markers and histochemical staining . Other mononuclear cells such as chicken thymocytes, nonadherent peripheral blood mononuclear cells, and chick embryo fibroblasts did not cause bone dissolution . In parallel with the active solubilization of bone mineral, 14C-label was also released from devitalized calvaria prelabeled with 14C-proline . Macrophages, inactivated by repeated freezing and thawing as well as those cultured in the presence of iodoacetate, did not solubilize bone in vitro . The degree of bone solubilization was directly related to the numbers of macrophages per culture as well as the duration of the culture period . Powdered devitalized homologous bone was used in most experiments, but macrophages were also able to solubilize bone material in vitro from devitalized calvaria and bone slabs . The addition of Escherichia coli lipopolysaccharide to cultures of bone and macrophages significantly increased the levels of calcium released from bone . The addition of parathyroid hormone and calcitonin had no effect on macrophage-mediated bone dissolution . These results suggest that viable macrophages have osteolytic activity and that this activity is modulated by an inflammatory mediator, endotoxin. Morphol Igazsagugyi Orv Sz, 1980 Apr, 20(2), 88 - 93 {Light and electron microscopic study of the seminiferous tubules in experimental malacoplakia}; Jarmay K et al.; Behaviour of the epithelium of seminiferous tubules and interstitial tissue was studied in malacoplakia induced by administration of an extract of E . coli . Necrosis of the epithelium of seminiferous tubules developed immediately and it was replaced by granulocytes, and histiocytes, phagocytizing both, bacterial extract administered and disintegrated cells . Tunica propria was thickened by inflammatory cells .