Abstract:
:Previously, the effects of three point mutations (at amino acid positions 31, 84, and 194) in the gene coding for a sulfonamide-resistant dihydropteroate synthase of Neisseria meningitidis were analyzed by site-directed mutagenesis. Changes at positions 31 and 194 abolished the phenotypic expression of sulfonamide resistance, while a change at position 84 appeared to be neutral. These studies are here extended to correlate the alterations in phenotype with effects on enzyme kinetics by expressing the cloned meningococcal genes in an Escherichia coli strain that had its dhps gene partially deleted and replaced by a resistance determinant. The most dramatic effects were produced by mutations at position 31. A change from the Leu found in the resistant isolate to a Phe (the residue found in sensitive isolates) led to a 10-fold decrease in the Km and a concomitant drop in the Ki. Changes at position 194 also affected both the Km and Ki but not to the same extent as mutations at position 31. Changing position 84 altered the Km only slightly but significantly. This latter change was interpreted as a compensatory change modulating the function of the enzyme. In another type of resistance gene, 2 amino acid residues, proposed to be an insertion, were deleted, resulting in a sensitive enzyme. However, the resulting Km was raised 10-fold, suggesting that compensatory changes have accumulated in this type of resistance determinant as well. This resistance gene differs by as much as 10% from the sensitive isolates, which makes identification of important mutations difficult.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Fermér C,Swedberg Gdoi
10.1128/jb.179.3.831-837.1997subject
Has Abstractpub_date
1997-02-01 00:00:00pages
831-7issue
3eissn
0021-9193issn
1098-5530journal_volume
179pub_type
杂志文章abstract::Vibrio alginolyticus contained two adjacent genes, ktrA and ktrB, which encode a new type of bacterial K(+)-uptake system. KtrA and KtrB are peripheral and integral membrane proteins, respectively. Six of the nine sequenced bacterial genomes contain homologs to both ktrA and ktrB, suggesting that KtrAB is widespread. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.13.3491-3494.1998
更新日期:1998-07-01 00:00:00
abstract::Genes involved in the biosynthesis of leucine have been mapped in Bacillus megaterium QM B1551, using transducing phage MP13. Mutations were designated leuA, leuB, or leuC on the basis of enzyme assays. Two mutant strains were deficient in the enzyme activities of leuA (alpha-isopropylmalate synthase) and leuC (beta-i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.157.2.454-459.1984
更新日期:1984-02-01 00:00:00
abstract::The 50S ribosomal subunits obtained from exponential-phase and valine-limited cultures of Streptococcus faecalis 9790 differed in protein content. Approximately 35% of the valine-limited subunits showed protein losses when analyzed by CsCl density centrifugation after formaldehyde fixation. Results of density gradient...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.105.1.190-199.1971
更新日期:1971-01-01 00:00:00
abstract::The Lyme disease agent Borrelia burgdorferi maintains both linear and circular plasmids that appear to be essential for mammalian infection. Recent studies have characterized the circular plasmid regions that confer autonomous replication, but the genetic elements necessary for linear plasmid maintenance have not been...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.10.3202-3209.2003
更新日期:2003-05-01 00:00:00
abstract::The participation of tyramine oxidase in the regulation of arylsulfatase synthesis in Salmonella typhimurium was studied. Arylsulfatase synthesis was repressed by inorganic sulfate, cysteine, methionine, or taurine. This repression was relieved by tyramine, octopamine, or dopamine, which induced tyramine oxidase synth...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.145.2.796-802.1981
更新日期:1981-02-01 00:00:00
abstract::Hottle, G. A. (Naval Biological Laboratory, University of California, Berkeley), and D. N. Wright. Growth and survival of Mycoplasma neurolyticum in liquid media. J. Bacteriol. 91:1834-1839. 1966.-Maximal growth of Mycoplasma neurolyticum (between 10(8) and 10(9) colony-forming units per ml) was obtained after 3 days ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.91.5.1834-1839.1966
更新日期:1966-05-01 00:00:00
abstract::When incubated in the light under 100% oxygen, wild-type blue-green algae (Anacystis nidulans, Synechococcus cedrorum) die out rapidly at temperatures of 4 to 15 C, and at 35 C (or at 26 C in the case of S. cedrorum) in the absence of CO(2). Photosynthesis is impaired in these cells long before they die. Blocking of p...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.111.3.682-689.1972
更新日期:1972-09-01 00:00:00
abstract::The pink yeast Rhodotorula rubra of marine origin was found to be capable of extended growth at very low phosphate concentrations (K(0.5) = 10.8 nm). Average intracellular phosphate concentrations, based on isotope exchange techniques, were 15 to 200 nm, giving concentration gradients across the cell envelope of about...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.2.599-611.1973
更新日期:1973-02-01 00:00:00
abstract::The inducible temperate bacteriophage phi75 and a clear-plaque-forming variant, phi75C1, mediated transduction of a 4.4 X 10(6)-dalton multicopy Bacillus pumilus plasmid, pPL10, at frequencies of 10(-5) to 10(-6) transductants per plaque-forming unit. phi75- and phi75C1-mediated transduction of several chromosome mark...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.131.3.1029-1032.1977
更新日期:1977-09-01 00:00:00
abstract::Neonatal bacterial meningitis continues to be an important cause of mortality and morbidity worldwide. Escherichia coli possessing the K1 capsular polysaccharide is the most common Gram-negative pathogen causing neonatal meningitis. Here we present the complete genome sequence of neonatal meningitis-associated E. coli...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06284-11
更新日期:2011-12-01 00:00:00
abstract::A group of enzymes were prepared from the culture fluids of streptococci belonging to groups A, B, C, G, and L, and from a strain of Streptococcus sanguis. These streptococcal enzymes (designated St-sialidases) released a substance shown to belong to the sialic acid group from the specific substrate BSM-St, a sialomuc...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.97.3.1328-1333.1969
更新日期:1969-03-01 00:00:00
abstract::A chromosomal insertion of transposon Tn917 partially restores the expression of protease and alpha-toxin activities to PM466, a genetically defined agr-null derivative of the wild-type Staphylococcus aureus strain RN6390. In co-transduction experiments, transposon-encoded erythromycin resistance and a protease- and a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.11.3197-3203.2000
更新日期:2000-06-01 00:00:00
abstract::The ability of different metal ions to promote transformation of Pseudomonas aeruginosa by deoxyribonucleic acid of the plasmid RP1 was examined. CaCl2, MgCl2, and MnCl2 were found to promote such transformation, although at different frequencies and with the optimum response at different concentrations. Only MgCl2 pr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.140.1.37-42.1979
更新日期:1979-10-01 00:00:00
abstract::Helicobacter pylori urease requires nickel ions in the enzyme active site for catalytic activity. Nickel ions must, therefore, be actively acquired by the bacterium. NixA (high-affinity nickel transport protein)-deficient mutants of H. pylori retain significant urease activity, suggesting the presence of alternate nic...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.18.5892-5902.1997
更新日期:1997-09-01 00:00:00
abstract::Cyclic nucleotide-independent protein kinase (EC 2.7.1.37) activity was found in the nuclear cap organelle, within which ribosomes of zoospores of Blastocladiella emersonii are sequestered. Two protein kinase activities were resolved from the high-salt wash fraction of zoospore ribosomes by selective adsorption to DEA...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.154.3.1467-1471.1983
更新日期:1983-06-01 00:00:00
abstract::The transposable drug resistance element Tn10 was employed as a region of homology to direct the insertion of Tn10-containing derivatives of F'ts114 lac into the chromosome of a Salmonella typhimurium strain that carries a Tn10 insertion in the histidine transport operon. Based on the direction of transfer of the resu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.157.3.697-702.1984
更新日期:1984-03-01 00:00:00
abstract::Halobacterium halobium spontaneously reverses its swimming direction with a frequency of about 0.1 s-1. The self-sustained periodicity can be entrained by rhythmic light stimuli within a limited range between 0.13 and 0.3 s-1. Increase of temperature increases the reversal frequency and shortens the time to reach maxi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.166.2.689-692.1986
更新日期:1986-05-01 00:00:00
abstract::Granular structures containing inorganic polyphosphate were found in Micrococcus lysodeikticus. These structures were isolated by fractionation of the bacterial extract obtained by lysing the organisms with lysozyme. The composition of the fraction which was enriched with these structures was found to be: protein, 24%...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.2.544-553.1968
更新日期:1968-08-01 00:00:00
abstract::The deacetylcephalosporin C synthetase (hydroxylase) gene from Streptomyces clavuligerus has been cloned and sequenced. The open reading frame codes for a protein with an Mr of 34,584. The hydroxylase gene (cefF) is closely linked to the epimerase gene (cefD) and the expandase gene (cefE) and is transcribed in the opp...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.1.398-400.1991
更新日期:1991-01-01 00:00:00
abstract::Mycoplasma pneumoniae exhibits a novel form of gliding motility that is mediated by the terminal organelle, a differentiated polar structure. Given that genes known to be involved in gliding in other organisms are absent in M. pneumoniae, random transposon mutagenesis was employed to generate mutants with gliding-defi...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02277-12
更新日期:2013-04-01 00:00:00
abstract::The gene GK3045 (741 bp) from Geobacillus kaustophilus HTA426 was cloned, sequenced, and overexpressed into Escherichia coli Rosetta (DE3). The deduced protein was a 30-kDa monomeric esterase with high homology to carboxylesterases from Geobacillus thermoleovorans NY (99% identity) and Geobacillus stearothermophilus (...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01060-08
更新日期:2009-05-01 00:00:00
abstract::Exoelectrogens are able to transfer electrons extracellularly, enabling them to respire on insoluble terminal electron acceptors. Extensively studied exoelectrogens, such as Geobacter sulfurreducens and Shewanella oneidensis, are Gram negative. More recently, it has been reported that Gram-positive bacteria, such as L...
journal_title:Journal of bacteriology
pub_type: 评论,杂志文章
doi:10.1128/JB.00029-20
更新日期:2020-03-11 00:00:00
abstract::sigma E is a sporulation-specific sigma factor of Bacillus subtilis that is formed from an inactive precursor protein (pro-sigma E) by the removal of 27 to 29 amino acids from the pro-sigma E amino terminus. By using oligonucleotide-directed mutagenesis, sequential deletions were constructed in the precursor-specific ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.14.4629-4637.1992
更新日期:1992-07-01 00:00:00
abstract::Genome comparisons have demonstrated that dramatic genetic change often underlies the emergence of new bacterial pathogens. Evolutionary analysis of Escherichia coli O157:H7, a pathogen that has emerged as a worldwide public health threat in the past two decades, has posited that this toxin-producing pathogen evolved ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.5.1783-1791.2005
更新日期:2005-03-01 00:00:00
abstract::Transcriptomic, metabolomic, physiological, and computational modeling approaches were integrated to gain insight into the mechanisms of antibiotic tolerance in an in vitro biofilm system. Pseudomonas aeruginosa biofilms were grown in drip flow reactors on a medium composed to mimic the exudate from a chronic wound. A...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00307-19
更新日期:2019-10-21 00:00:00
abstract::The formation of recombinants in Hfr crosses was studied in Escherichia coli strains carrying combinations of genes known to affect recombination and DNA repair. Mutations in ruv and recG eliminate activities that have been shown to process Holliday junction intermediates by nuclease cleavage and/or branch migration. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.6.1570-1577.1994
更新日期:1994-03-01 00:00:00
abstract::Polyphosphate of average chain length corresponding to 10 phosphate units was detected in the mycelial extract of zygomycetes. Gel electrophoresis techniques commonly used for the separation and characterization of acidic mucopolysaccharides were successfully used for the detection, purification, and characterization ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.127.3.1408-1413.1976
更新日期:1976-09-01 00:00:00
abstract::The bacterium Caulobacter crescentus undergoes an asymmetric cell division resulting in the formation of two different daughter cells, a motile swarmer cell and a nonmotile stalked cell. These two cell types differ in their program of gene expression, their ability to replicate DNA, and the physical properties of thei...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.21.6970-6981.1993
更新日期:1993-11-01 00:00:00
abstract::Shewanella oneidensis MR-1 is a facultatively anaerobic bacterium capable of using soluble and insoluble forms of manganese [Mn(III/IV)] and iron [Fe(III)] as terminal electron acceptors during anaerobic respiration. To assess the structural association of two outer membrane-associated c-type decaheme cytochromes (i.e...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01966-05
更新日期:2006-07-01 00:00:00
abstract::A study was made to determine whether factors other than the availability of phosphorus were involved in the regulation of synthesis of teichoic and teichuronic acids in Bacillus subtilis subsp. niger WM. First, the nature of the carbon source was varied while the dilution rate was maintained at about 0.3 h-1. Irrespe...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.144.1.238-246.1980
更新日期:1980-10-01 00:00:00