Abstract:
:The metabolism of mRNA from the lactose (lac) operon of Escherichia coli has been studied in ribonuclease (RNase) III-deficient strains (rnc-105). The induction lag for beta-galactosidase from the first gene was twice as long, and enzyme synthesis was reduced 10-fold in one such mutant compared with its isogenic rnc+ sister; in the original mutant strain AB301-105, synthesis of beta-galactosidase was not even detectable, although transduction analysis revealed the presence of a normal lac operon. This defect does not reflect a loss of all lac operon activity galactoside acetyltransferase from the last gene was synthesized even in strain AB301-105 but at a rate several times lower than normal. Hybridization analyses suggested that both the frequency of transcription initiation and the time to transcribe the entire operon are normal in rnc-105 strains. The long induction lag was caused by a longer translation time. This defect led to translational polarity with reduced amounts of distal mRNA to give a population of smaller-sized lac mRNA molecules. All these pleiotropic effects seem to result from RNase III deficiency, since it was possible to select revertants to rnc+ that grew and expressed the lac operon at normal rates. However, the rnc-105 isogenic strains (but not AB301-105) also changed very easily to give a more normal rate of beta-galactosidase synthesis without regaining RNase III activity or a faster growth rate. The basis for this reversion is not known; it may represent a "phenotypic suppression" rather than result from a stable genetic change. Such suppressor effects could account for earlier reports of a noninvolvement of RNase III in mRNA metabolism in deliberately selected lac+ rnc-105 strains. The ribosomes from rnc-105 strains were as competent as ribosomes from rnc+ strains to form translation initiation complexes in vitro. However, per mass, beta-galactosidase mRNA from AB301-105 was at least three times less competent to form initiation complexes than was A19 beta-galactosidase mRNA. RNase III may be important in the normal cell to prepare lac mRNA for translation initiation. A defect at this step could account for all the observed changes in lac expression. A potential target within a secondary structure at the start of the lac mRNA is considered. Expression of many operons may be affected by RNase III activity; gal and trp operon expressions were also abnormal in RNase III- strains.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Talkad V,Achord D,Kennell Ddoi
10.1128/JB.135.2.528-541.1978subject
Has Abstractpub_date
1978-08-01 00:00:00pages
528-41issue
2eissn
0021-9193issn
1098-5530journal_volume
135pub_type
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journal_title:Journal of bacteriology
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doi:10.1128/jb.173.15.4558-4569.1991
更新日期:1991-08-01 00:00:00
abstract::The reactive alpha-oxoaldehydes such as glyoxal (GO) and methylglyoxal (MG) are generated in vivo from sugars through oxidative stress. GO and MG are believed to be removed from cells by glutathione-dependent glyoxalases and other aldehyde reductases. We isolated a number of GO-resistant (GO(r)) mutants from Escherich...
journal_title:Journal of bacteriology
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doi:10.1128/JB.01127-09
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journal_title:Journal of bacteriology
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更新日期:1969-05-01 00:00:00
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doi:10.1128/JB.06038-11
更新日期:2011-12-01 00:00:00
abstract::Direct evidence for the involvement of ubiquinone in H2 oxidation by Rhizobium japonicum was demonstrated; H2 reduced ca. 80% of the extractable ubiquinone. The inhibitor 2-n-heptyl-4-hydroxyquinoline-N-oxide blocked electron transport at a site between ubiquinone and the cytochromes. The results showed that no cytoch...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.2.775-777.1985
更新日期:1985-02-01 00:00:00
abstract::Genetic and segregation analysis of Escherichia coli strains containing a partial duplication of the trp operon reveal that the 2.5-min-long region trpD-purB is duplicated in tandem in the chromosome. The adjacent loci cysB and fabD are not duplicated. Although one copy of the duplicated region is longer than the maxi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.2.650-660.1978
更新日期:1978-02-01 00:00:00
abstract::The synthesis of pyruvate carboxylase (PC) was studied by using quantitative immunoblot analysis with an antibody raised against PC purified from Rhodobacter capsulatus and was found to vary 20-fold depending on the growth conditions. The PC content was high in cells grown on pyruvate or on carbon substrates metaboliz...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.5.1460-1468.1997
更新日期:1997-03-01 00:00:00
abstract::A rare group I intron in a cyanobacterial ribonucleotide reductase gene has been characterized. It contains a mobile insertion sequence element not required for RNA splicing. Ribonucleotide reductase genes were found to be hot spots for all three types of self-splicing intervening sequences, including group I and II i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01424-06
更新日期:2007-03-01 00:00:00
abstract::Davies, Helen C. (University of Pennsylvania, Philadelphia), Fred Karush, and Joanne H. Rudd. Effect of amino acids on steady-state growth of a group A hemolytic streptococcus. J. Bacteriol. 89:421-427. 1965.-A study has been made of amino acid utilization by a strain of type 4, group A streptococcus growing under ste...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:
更新日期:1965-02-01 00:00:00
abstract::The alkaline phosphatases of 29 strains of bacteria assigned by various authors to the genera Aerobacter, Klebsiella and Enterobacter were compared by the micro-complement fixation technique. On the basis of phosphatase resemblance, we recommend that all strains hitherto assigned to Aerobacter aerogenes and Enterobact...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.110.3.803-808.1972
更新日期:1972-06-01 00:00:00
abstract::Helicobacter pylori strains can be divided into two groups, based on the presence of two unrelated genes, iceA1 and iceA2, that occupy the same genomic locus. hpyIM, located immediately downstream of either gene, encodes a functional CATG-specific methyltransferase. Despite the strong conservation of the hpyIM open re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.13.3875-3884.2001
更新日期:2001-07-01 00:00:00
abstract::The effects of starving Escherichia coli for glucose and required amino acids were determined. The disappearance of the majority of the ribosomal population, particularly of the ribonucleic acid (RNA) moiety, was noted. The events during recovery are detailed, with emphasis placed on the timing, requirements, and cont...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.3.1030-1039.1968
更新日期:1968-03-01 00:00:00
abstract::Escherichia coli O111a is a thermosensitive strain which, when grown at 40 C, accumulates large quantities of intracellular membranes. The ultrastructure of these membranes in cells which have been chemically fixed, embedded, and examined as thin sections has been compared with that of membranes in cells negatively st...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.1.433-444.1973
更新日期:1973-01-01 00:00:00
abstract::Sialidase activity varies widely among strains and tends to correlate with strain virulence in the avian pathogen Mycoplasma synoviae. To characterize the forms of selection acting on enzymes required for sialic acid scavenging and catabolism, the ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequency ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00142-09
更新日期:2009-06-01 00:00:00
abstract::The abundance of oxidants and reductants must be balanced for an organism to thrive. Bacteria have evolved methods to prevent redox imbalances and to mitigate their deleterious consequences through the expression of detoxification enzymes, antioxidants, and systems to repair or degrade damaged proteins and DNA. Regula...
journal_title:Journal of bacteriology
pub_type: 杂志文章,评审
doi:10.1128/JB.00128-18
更新日期:2018-08-10 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.14.4520-4527.1993
更新日期:1993-07-01 00:00:00
abstract::A polA12 recA718 double mutant of Escherichia coli, in which DNA polymerase I is temperature sensitive, was unable to maintain normal DNA synthesis or to form colonies on rich media at 42 degrees C. Overproduction of DnaE protein, the polymerizing alpha subunit of DNA polymerase III, restored bacterial DNA replication...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.12.4166-4168.1992
更新日期:1992-06-01 00:00:00
abstract::The binding of Bacteroides intermedius VPI 8944 to human fibrinogen has been characterized. The binding is time dependent, at least partially reversible, saturable, and specific. On an average, a maximum of 3,500 fibrinogen molecules bind per bacterial cell, with a dissociation constant of 1.7 X 10(-11) M. These bacte...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.163.2.623-628.1985
更新日期:1985-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.12.3723-3729.1994
更新日期:1994-06-01 00:00:00
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journal_title:Journal of bacteriology
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更新日期:2003-04-01 00:00:00
abstract::The cloned gene coding for Bacillus licheniformis penicillinase (penP) was introduced into Escherichia coli in a heat-inducible lambda Qam vector. After induction, significant amounts of penicillinase were synthesized in the new host. The cellular location of the penicillinase was found to be almost exclusively the ou...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.155.2.657-663.1983
更新日期:1983-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00597-19
更新日期:2020-01-15 00:00:00
abstract::The isopropylmalate isomerase in Salmonella typhimurium is the second enzyme specific for leucine biosynthesis. It is a complex enzyme composed of two subunits which are coded for by two genes of the leucine operon, leuC and leuD. The two polypeptides have been shown to copurify through successive ammonium sulfate fra...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.148.1.210-219.1981
更新日期:1981-10-01 00:00:00
abstract::Shigella flexneri is a gram-negative bacterium that causes diarrhea and dysentery by invasion and spread through the colonic epithelium. Bacteria spread by assembling actin and other cytoskeletal proteins of the host into "actin tails" at the bacterial pole; actin tail assembly provides the force required to move bact...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.3.869-878.1999
更新日期:1999-02-01 00:00:00
abstract::The gene responsible for the uncommon glutamate dehydrogenase (GDH) activity of Lactococcus lactis was identified and characterized. It encodes a GDH of family I that is mainly active in glutamate biosynthesis, is carried by a large plasmid, and is included, with functional cadmium resistance genes, in a remnant Tn3-l...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.14.5019-5022.2005
更新日期:2005-07-01 00:00:00
abstract::Cupric sulfate induced mRNA specific to the copper resistance gene cluster previously cloned from Pseudomonas syringae pv. tomato PT23. mRNA from each of the four genes of this cluster responded in a similar manner to induction over time and with different concentrations of cupric sulfate. Promoter fusion constructs i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.9.4399-4401.1988
更新日期:1988-09-01 00:00:00
abstract::Graber, C. D. (Baylor University College of Medicine, Houston, Tex.), R. M. O'Neal, and E. R. Rabin. Effect of high fat diets on intestinal microflora and serum cholesterol in rats. J. Bacteriol. 89:47-51. 1965.-Differential bacterial counts of feces and total plasma cholesterol determinations were performed on 60 Wis...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.89.1.47-51.1965
更新日期:1965-01-01 00:00:00
abstract::Pfs expression is required for several metabolic pathways and limits the production of autoinducer-2, a molecule proposed to play a central role in interspecies quorum sensing. The present study reveals physiological conditions and promoter DNA elements that regulate Escherichia coli pfs transcription. Pfs transcripti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00868-06
更新日期:2006-11-01 00:00:00
abstract::The high-potential 4Fe-4S* center ofAzotobacter vinelandii ferredoxin I has been titrated potentiometrically by a reductive procedure. The absorbance decrease at 510 nm accompanying the reduction of the high-potential center titrated with an Em of 320 mV (n = 1). The low-potential 4Fe-4S* center was titrated by using ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.136.2.822-824.1978
更新日期:1978-11-01 00:00:00
abstract::Cells of the cyanobacterium Anabaena variabilis starved for phosphate for 3 days took up phosphate at about 100 times the rate of unstarved cells. Kinetic data suggested that a new transport system had been induced by starvation for phosphate. The inducible phosphate transport system was quickly repressed by addition ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.3.1143-1147.1988
更新日期:1988-03-01 00:00:00