Abstract:
:Site-directed mutagenesis has been employed to address the functional significance of the highly conserved aspartic and glutamic acid residues present in the Walker B (also called motif II) sequence in Escherichia coli DNA helicase II. Two mutant proteins, UvrDE221Q and UvrDD220NE221Q, were expressed and purified to apparent homogeneity. Biochemical characterization of the DNA-dependent ATPase activity of each mutant protein demonstrated a kcat that was < 0.5% of that of the wild-type protein, with no significant change in the apparent Km for ATP. The E221Q mutant protein exhibited no detectable unwinding of either partial duplex or blunt duplex DNA substrates. The D220NE221Q mutant, however, catalyzed unwinding of both partial duplex and blunt duplex substrates, but at a greatly reduced rate compared with that of the wild-type enzyme. Both mutants were able to bind DNA. Thus, the motif II mutants E221Q and D220NE221Q were able to bind ATP and DNA to the same extent as wild-type helicase II but demonstrate a significant reduction in ATP hydrolysis and helicase functions. The mutant uvrD alleles were also characterized by examining their abilities to complement the mutator and UV light-sensitive phenotypes of a uvrD deletion mutant. Neither the uvrDE221Q nor the uvrDD220NE221Q allele, supplied on a plasmid, was able to complement either phenotype. Further genetic characterization of the mutant uvrD alleles demonstrated that uvrDE221Q confers a dominant negative growth phenotype; the uvrDD220NE221Q allele does not exhibit this effect. The observed difference in effect on viability may reflect the gene products' dissimilar kinetics for unwinding duplex DNA substrates in vitro.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Brosh RM Jr,Matson SWdoi
10.1128/jb.177.19.5612-5621.1995subject
Has Abstractpub_date
1995-10-01 00:00:00pages
5612-21issue
19eissn
0021-9193issn
1098-5530journal_volume
177pub_type
杂志文章abstract::The major structural components of the P2 contractile tail are encoded in the FETUD tail gene operon. The sequences of genes F(I) and F(II), encoding the major tail sheath and tail tube proteins, have been reported previously (L. M. Temple, S. L. Forsburg, R. Calendar, and G. E. Christie, Virology 181:353-358, 1991). ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.23.6522-6531.2002
更新日期:2002-12-01 00:00:00
abstract::Our previous work showed that pap pilin gene transcription is subject to a thermoregulatory control mechanism under which pap pilin is not transcribed at a low temperature (23 degrees C) (L. B. Blyn, B. A. Braaten, C. A. White-Ziegler, D. H. Rolfson, and D. A. Low, EMBO J. 8:613-620, 1989). In order to isolate genes i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.21.7003-7012.1992
更新日期:1992-11-01 00:00:00
abstract::Pathways of mannitol biosynthesis and utilization in Aspergillus candidus NRRL 305 were studied in cell-free extracts of washed mycelia prepared by sonic and French pressure cell treatments. A nicotinamide adenine dinucleotide-linked mannitol-1-phosphate (M1P) dehydrogenase was found in French pressure cell extracts o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.97.3.1305-1309.1969
更新日期:1969-03-01 00:00:00
abstract::The 56-kb class II toluene catabolic transposon Tn4651 from Pseudomonas putida plasmid pWW0 is unique in that (i) its efficient resolution requires, in addition to the 0.2-kb resolution (res) site, the two gene products TnpS and TnpT and (ii) the 2.4-kb tnpT-res-tnpS region is 48 kb apart from the tnpA gene (M. Tsuda,...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.17.4757-4766.2002
更新日期:2002-09-01 00:00:00
abstract::Methyl coenzyme M methylreductase from acetate-grown Methanosarcina thermophila TM-1 was purified 16-fold from a cell extract to apparent homogeneity as determined by native polyacrylamide gel electrophoresis. Ninety-four percent of the methylreductase activity was recovered in the soluble fraction of cell extracts. T...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.8.2481-2487.1991
更新日期:1991-04-01 00:00:00
abstract::Necrotic enteritis (NE) is an economically important disease of poultry caused by certain Clostridium perfringens type A strains. NE pathogenesis involves the NetB toxin, which is encoded on a large conjugative plasmid within a 42-kb pathogenicity locus. Recent multilocus sequence type (MLST) studies have identified t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01032-12
更新日期:2013-03-01 00:00:00
abstract::This work describes the draft genome sequence of Lactococcus garvieae DCC43. The 2.2-Mb draft genome contains 2,227 predicted protein-coding genes, among which is a region encoding the bacteriocin garvicin ML. No antibiotic resistance genes or capsule-related virulence genes were identified. Two plasmid replication re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01864-12
更新日期:2012-12-01 00:00:00
abstract::Streptomyces coelicolor Müller contains two superoxide dismutases (SODs), nickel-containing (NiSOD) and iron- and zinc-containing SOD (FeZnSOD). The sodF gene encoding FeZnSOD was isolated by using PCR primers corresponding to the N-terminal peptide sequence of the purified FeZnSOD and a C-terminal region conserved am...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.8.2014-2020.1998
更新日期:1998-04-01 00:00:00
abstract::We report a phenomenon similar to catabolite repression in Rhizobium meliloti. Succinate, which allows the highest observed rate of growth of R. meliloti, caused an immediate reduction of beta-galactosidase activity when added to cells growing in lactose. A Lac- mutant was unaltered in nodulation and nitrogen fixation...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.136.3.1197-1200.1978
更新日期:1978-12-01 00:00:00
abstract::A protein carboxyl methyltransferase (EC 2.1.1.77) that recognizes age-damaged proteins for potential repair or degradation reactions has been found in all vertebrate tissues and cells examined to date. This enzyme catalyzes the transfer of methyl groups from S-adenosylmethionine to the carboxyl groups of D-aspartyl o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.2.355-361.1992
更新日期:1992-01-01 00:00:00
abstract::The Rhodobacter capsulatus genome contains three genes (olsA [plsC138], plsC316, and plsC3498) that are annotated as lysophosphatidic acid (1-acyl-sn-glycerol-3-phosphate) acyltransferase (AGPAT). Of these genes, olsA was previously shown to be an O-acyltransferase in the second step of ornithine lipid biosynthesis, w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01121-07
更新日期:2007-12-01 00:00:00
abstract::Escherichia coli MutY and MutS increase replication fidelity by removing adenines that were misincorporated opposite 7,8-dihydro-8-oxo-deoxyguanines (8-oxoG), G, or C. MutY DNA glycosylase removes adenines from these mismatches through a short-patch base excision repair pathway and thus prevents G:C-to-T:A and A:T-to-...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01513-06
更新日期:2007-02-01 00:00:00
abstract::Lactococcus garvieae is the etiological agent of lactococcosis, one of the most important disease threats to the sustainability of the rainbow trout farming industry. Here, we present the draft genome sequence of Lactococcus garvieae strain 8831, isolated from diseased rainbow trout, which is composed of 2,087,276 bp ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05326-11
更新日期:2011-08-01 00:00:00
abstract::Listeria monocytogenes mutants with deletions in aroA, aroB, or aroE exhibited strong posttranscriptional upregulation of internalin A (InlA) and InlB synthesis, which resulted in a more-than-10-fold increase in InlA-mediated internalization by epithelial Caco-2 cells and a 4-fold increase in InlB-mediated internaliza...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.8.2836-2845.2005
更新日期:2005-04-01 00:00:00
abstract::Mycelial mats of Ascodesmis sphaerospora were fixed and embedded for electron microscopy, and thin sections of 1-mm blocks, taken from the 1st to the 7th mm behind the hyphal tips, were cut parallel to the long axis of the hyphae. The hyphal tip region is characterized by an outer zone of electron-transparent vesicles...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.2.658-671.1968
更新日期:1968-02-01 00:00:00
abstract::Electron cryotomography was used to analyze the structure of the Lyme disease spirochete, Borrelia burgdorferi. This methodology offers a new means for studying the native architecture of bacteria by eliminating the chemical fixing, dehydration, and staining steps of conventional electron microscopy. Using electron cr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01288-08
更新日期:2009-01-01 00:00:00
abstract::In a previous paper it was shown that cocultivation of Rhizobium leguminosarum with the plant Vicia sativa subsp. nigra on solid medium causes a changed mode of growth of the plant roots, resulting in thick and short roots (Tsr). The Sym plasmid present in the bacterium appeared to be essential for causing Tsr (A. A. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.165.2.517-522.1986
更新日期:1986-02-01 00:00:00
abstract::The ski22::Tn917lac insertion mutation in Bacillus subtilis was isolated in a screen for mutations that cause a defect in sporulation but are suppressed by the presence or overexpression of the histidine protein kinase encoded by kinA (spoIIJ). The ski22::Tn917lac insertion mutation was in ald, the gene encoding alani...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.21.6789-6796.1993
更新日期:1993-11-01 00:00:00
abstract::DifA is a methyl-accepting chemotaxis protein (MCP)-like sensory transducer that regulates exopolysaccharide (EPS) production in Myxococcus xanthus. Here mutational analysis and molecular biology were used to probe the signaling mechanisms of DifA in EPS regulation. We first identified the start codon of DifA experime...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00944-10
更新日期:2011-02-01 00:00:00
abstract::The cyclic dinucleotides cyclic 3′,5′-diguanylate (c-di-GMP) and cyclic 3′,5′-diadenylate (c-di-AMP) have emerged as key components of bacterial signal transduction networks. These closely related second messengers follow the classical general principles of nucleotide signaling by integrating diverse signals into regu...
journal_title:Journal of bacteriology
pub_type: 杂志文章,评审
doi:10.1128/JB.00423-15
更新日期:2016-01-01 00:00:00
abstract::High-affinity iron acquisition in Bacillus subtilis is mediated via the bacillibactin catechole siderophore pathway. Three of the four essential pathway steps, bacillibactin synthesis, Fe-bacillibactin uptake, and Fe-bacillibactin hydrolysis have been characterized previously. The functional and regulatory components ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00464-08
更新日期:2008-08-01 00:00:00
abstract::The experiments presented in this paper suggest that the shift observed in sedimentation of deoxyribonucleic acid from cells of Escherichia coli subjected to amino acid starvation is related to inhibition of ribonucleic acid synthesis rather than to its release from the membrane at the termination of replication. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.137.2.790-794.1979
更新日期:1979-02-01 00:00:00
abstract::A thermosensitive episome bearing the transposon Tn10, F(Ts)::Tn10 Lac+, has been successfully transferred from Escherichia coli to several wild strains of the enterobacteria Erwinia carotovora subsp. chrysanthemi, which are pathogenic on Saintpaulia ionantha. In one of these strains, all of the characters controlled ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.150.1.122-131.1982
更新日期:1982-04-01 00:00:00
abstract::Alicyclobacillus acidocaldarius strain Tc-4-1 was initially isolated from a hot spring in Tengchong, China. This organism is both thermophilic and acidophilic. It can produce heat- and acid-stable enzymes, such as amylase and esterase, which may be important in industry. Here we report the whole genome sequence of the...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05709-11
更新日期:2011-10-01 00:00:00
abstract::The transfer of plasmid DNA molecules between bacterial cells is achieved by a large array of conjugative transfer proteins which assemble into both cytoplasmic and membrane-associated complexes. TrhC is a membrane-associated protein that is required for the transfer of the IncHI1 resistance plasmid R27. Homologous pr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.6.1606-1613.2004
更新日期:2004-03-01 00:00:00
abstract::The two-partner secretion system ExlBA, expressed by strains of Pseudomonas aeruginosa belonging to the PA7 group, induces hemorrhage in lungs due to disruption of host cellular membranes. Here we demonstrate that the exlBA genes are controlled by a pathway consisting of cAMP and the virulence factor regulator (Vfr). ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00135-18
更新日期:2018-05-24 00:00:00
abstract::Welker, N. E. (University of Illinois, Urbana), and L. Leon Campbell. Biochemical changes in lysogenic Bacillus stearothermophilus after bacteriophage induction. J. Bacteriol. 90:1129-1137. 1965.-Cultures of Bacillus stearothermophilus 1503-4R (TP-1) continued to grow at an unaltered rate after induction with mitomyci...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.90.4.1129-1137.1965
更新日期:1965-10-01 00:00:00
abstract::MreC and MreD, along with the actin homologue MreB, are required to maintain the shape of rod-shaped bacteria. The depletion of MreCD in rod-shaped bacteria leads to the formation of spherical cells and the accumulation of suppressor mutations. Ovococcus bacteria, such as Streptococcus pneumoniae, lack MreB homologues...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05245-11
更新日期:2011-08-01 00:00:00
abstract::The lic3 locus of Haemophilus influenzae consists of four open reading frames. The derived amino acid sequences of orf2 and orf4 exhibit homology to Escherichia coli GalE and AdK, respectively. The functions of orf1 and orf3 remain unknown. orf1 contains multiple tandem repeats of the tetrameric DNA sequence CAAT near...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.22.7245-7252.1992
更新日期:1992-11-01 00:00:00
abstract::Members of all four families of methanogenic bacteria were analyzed for polyamine concentrations. High-performance liquid chromatography analysis of dansylated cell extracts revealed typical polyamine patterns for each family. Members of Methanobacteriaceae (family I) were characterized by very low polyamine concentra...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.154.3.1315-1322.1983
更新日期:1983-06-01 00:00:00