Abstract:
:This study describes the isolation and characterization of a unique class of TolC mutants that, under steady-state growth conditions, secreted normal levels of largely inactive alpha-hemolysin. Unlike the reduced activity in the culture supernatants, the cell-associated hemolytic activity in these mutants was identical to that in the parental strain, thus reflecting a normal intracellular toxin activation event. Treatment of the secreted toxin with guanidine hydrochloride significantly restored cytolytic activity, suggesting that the diminished activity may have been due to the aggregation or misfolding of the toxin molecules. Consistent with this notion, sedimentation and filtration analyses showed that alpha-hemolysin secreted from the mutant strain has a mass greater than that secreted from the parental strain. Experiments designed to monitor the time course of alpha-hemolysin release showed delayed appearance of toxin in the culture supernatant of the mutant strain, thus indicating a possible defect in alpha-hemolysin translocation or release. Eight different TolC substitutions displaying this toxin secretion defect were scattered throughout the protein, of which six localized in the periplasmically exposed alpha-helical domain, while the remaining two mapped within the outer membrane-embedded beta-barrel domain of TolC. A plausible model for the secretion of inactive alpha-hemolysin in these TolC mutants is discussed in the context of the recently determined three-dimensional structure of TolC.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Vakharia H,German GJ,Misra Rdoi
10.1128/JB.183.23.6908-6916.2001keywords:
subject
Has Abstractpub_date
2001-12-01 00:00:00pages
6908-16issue
23eissn
0021-9193issn
1098-5530journal_volume
183pub_type
杂志文章abstract::Cyclic 2,3-diphosphoglycerate synthetase (cDPGS) catalyzes the synthesis of cyclic 2,3-diphosphoglycerate (cDPG) by formation of an intramolecular phosphoanhydride bond in 2,3-diphosphoglycerate. cDPG is known to be accumulated to high intracellular concentrations (>300 mM) as a putative thermoadapter in some hyperthe...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.22.5997-6004.1998
更新日期:1998-11-01 00:00:00
abstract::Antiserum prepared against protocatechuate 3, 4-dioxygenase from Pseudomonas aeruginosa forms precipitin bands without spurs with isofunctional enzymes from different strains of the fluorescent pseudomonads on immunodiffusion plates. Catalytic activity of the isofunctional enzymes was inhibited by an immunoglobulin fr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.126.1.516-519.1976
更新日期:1976-04-01 00:00:00
abstract::We purified membrane-bound cytochrome c-550 [cytochrome c-550(m)] to an electrophoretically homogeneous state from Nitrobacter winogradskyi. The cytochrome showed peaks at 409 and 525 nm in the oxidized form and peaks at 416, 521, and 550 nm in the reduced form. The molecular weight of the cytochrome was estimated to ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.14.4400-4404.1993
更新日期:1993-07-01 00:00:00
abstract::The content and distribution of autolysin were measured in temperature-sensitive morphological mutants of Bacillus subtilis. Strains RUB1000 and RUB1012 grew as rods at 30 C. At 45 C the mutants contained disproportionately less teichoic acid than peptidoglycan and grew as irregular spheres. The amount of enzyme that ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.125.1.166-173.1976
更新日期:1976-01-01 00:00:00
abstract::The nucleotide sequence of a 7.3-kilobase-pair fragment of DNA encoding a hemolytic activity from Serratia marcescens was determined. Two large open reading frames were identified, designated shlA (Serratia hemolysin) and shlB, capable of encoding polypeptides of 165, 056 and 61,897 molecular weight, respectively. Bot...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.7.3177-3188.1988
更新日期:1988-07-01 00:00:00
abstract::trpG of Bacillus subtilis encodes a glutamine amidotransferase subunit that is involved in the synthesis of both folic acid and L-tryptophan. Expression of trpG is negatively regulated by tryptophan even though this gene is located within a folic acid biosynthetic operon. Examination of both transcriptional and transl...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.15.4272-4278.1995
更新日期:1995-08-01 00:00:00
abstract::A new method for measuring the secretion of H(2)O(2) has been based upon an H(2)O(2)-dependent inhibition of catalase by 3-amino-1,2,4-triazole. The conversion of an H(2)O(2)-secretion rate into a catalase inhibition rate amplified a relatively small molar concentration of H(2)O(2) and provided a highly specific and s...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.98.2.543-546.1969
更新日期:1969-05-01 00:00:00
abstract::We report the draft genome sequence of Paenisporosarcina sp. strain TG-20, which is 4.12 Mb in size and consists of 4,071 protein-coding genes and 76 RNA genes. The genome sequence of Paenisporosarcina sp. TG-20 may provide useful information about molecular adaptations that enhance survival in icy subsurface environm...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01472-12
更新日期:2012-12-01 00:00:00
abstract::A characteristic of N2-fixing cyanobacteria in symbiotic associations appears to be release of N2-derived NH4+. The specific activity of the primary ammonium-assimilating enzyme, glutamine synthetase (GS), was found to be three- to fourfold lower in Nostoc sp. strain 7801 grown in symbiotic association with the bryoph...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.6.2471-2475.1987
更新日期:1987-06-01 00:00:00
abstract::Subgenomic DNA microarrays were employed to evaluate the expression of the accessory gene regulator (agr locus) as well as multiple virulence-associated genes in Staphylococcus aureus. Gene expression was examined during growth of S. aureus in vitro in standard laboratory medium and rabbit serum and in vivo in subcuta...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.4.1095-1101.2002
更新日期:2002-02-01 00:00:00
abstract::Ben-Hamida, Fakher (Washington University School of Medicine, St. Louis, Mo.), and David Schlessinger. Stability of beta-galactosidase messenger ribonucleic acid in Escherichia coli. J. Bacteriol. 90:1611-1616. 1965.-Synthesis of beta-galactosidase stops within several minutes when preinduced, permeaseless cultures ar...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.90.6.1611-1616.1965
更新日期:1965-12-01 00:00:00
abstract::The chpB locus is a chromosomal homolog of the pem locus, which is responsible for stable maintenance of plasmid R100 within the host cells. Like pem, chpB codes for two genes, chpBK and chpBI, encoding a growth inhibitor and a suppressor for the killing action of the ChpBK protein, respectively. Here, we determined t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.18.5861-5863.1994
更新日期:1994-09-01 00:00:00
abstract::The Haemophilus influenzae Rd rec-1+ gene was cloned from a partial chromosomal digest into a plasmid vector as a 20-kilobase-pair (kbp) BstEII fragment and then subcloned. The smallest subclone with rec-1+ activity carried a 3.1-kbp EcoRI fragment. The identity of the rec-I gene in these clones was confirmed by trans...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.8.4395-4401.1989
更新日期:1989-08-01 00:00:00
abstract::Multicopy single-stranded DNA is found as a small single-stranded RNA-DNA complex in certain wild-type strains of Escherichia coli as well as in other gram-negative bacteria. Using the promoter region of the previously characterized retron-Ec107 from E. coli ECOR70, I constructed a chromosomally located lacZ operon fu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.15.4438-4444.1996
更新日期:1996-08-01 00:00:00
abstract::Herman, Alberta (University of Wisconsin, Madison) and Harlyn Halvorson. Identification of the structural gene for beta-glucosidase in Saccharomyces lactis. J. Bacteriol. 85:895-900. 1963.-Three allelic forms (B(h, m, l)) of the structural gene for beta-glucosidase have been identified in the yeast Saccharomyces lacti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.85.4.895-900.1963
更新日期:1963-04-01 00:00:00
abstract::Thermococcus sp. strain 4557 is a hyperthermophilic anaerobic archaeon isolated from the deep-sea hydrothermal vent Guaymas Basin site in the Gulf of California at a depth of 2,000 m. Here, we present the complete genome sequence of Thermococcus sp. 4557, which consists of a single circular chromosome of 2,011,320 bp ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05851-11
更新日期:2011-10-01 00:00:00
abstract::Gene sequences encoding the enzymes UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from many bacterial sources were analyzed. It was shown that whereas gram-negative bacteria have only one murA gene, gram-positive bacteria have two distinct genes encoding these enzymes which have possibly arisen from gene dupl...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.15.4146-4152.2000
更新日期:2000-08-01 00:00:00
abstract::When Bacillus subtilis is subjected to phosphate starvation, genes of the Pho regulon are either induced or repressed. Among those induced are genes encoding alkaline phosphatases (APases). A set of isogenic mutants, with a beta-galactosidase gene transcriptionally fused to the inactivated target gene, was used to ide...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.8.2505-2515.2001
更新日期:2001-04-01 00:00:00
abstract::A cell permeabilization procedure is described that reduces viability less than 10% and does not significantly reduce the rates of ribonucleic acid and protein synthesis when appropriately supplemented. Permeabilization abolishes the normal stringent coupling of protein and ribonucleic acid synthesis. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.3.1186-1189.1974
更新日期:1974-06-01 00:00:00
abstract::A 7.5-kbp fragment of chromosomal DNA downstream of the Vibrio cholerae vibriobactin outer membrane receptor, viuA, and the vibriobactin utilization gene, viuB, was recovered from a Sau3A lambda library of O395 chromosomal DNA. By analogy with the genetic organization of the Escherichia coli enterobactin gene cluster,...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.6.1731-1738.2000
更新日期:2000-03-01 00:00:00
abstract::Nonpiliated, phage phi 6-resistant mutants of Pseudomonas syringae pv. phaseolicola were generated by Tn5 transposon mutagenesis. A P. syringae pv. phaseolicola LR700 cosmid library was screened with Tn5-containing EcoRI fragments cloned from nonpiliated mutants. The cosmid clone pVK253 complemented the nonpiliated mu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.2.410-417.1996
更新日期:1996-01-01 00:00:00
abstract::FabG performs the NADPH-dependent reduction of β-keto acyl-acyl carrier protein substrates in the elongation cycle of fatty acid synthesis. We report the characterization of a temperature-sensitive mutation (fabGΔ8) in Escherichia colifabG that results from an in-frame 8-amino-acid residue deletion in the α6/α7 subdom...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00074-17
更新日期:2017-04-25 00:00:00
abstract::Riemerella anatipestifer is responsible for exudative septicemia in ducks. The genetic determinant of the CAMP cohemolysin, cam, from a strain of R. anatipestifer was cloned and expressed in Escherichia coli. Chromosomal DNA from serotype 19 strain 30/90 was used to construct a gene library in pBluescript II SK(-) vec...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.7.1932-1939.2002
更新日期:2002-04-01 00:00:00
abstract::Regulation of the katB catalase gene in the anaerobic bacterium Bacteroides fragilis was studied. Northern blot hybridization analyses revealed that katB was transcribed as an approximately 1.6-kb monocistronic mRNA. The levels of katB mRNA increased > 15-fold when anaerobic, mid-logarithmic-phase cultures were expose...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.22.7033-7039.1997
更新日期:1997-11-01 00:00:00
abstract::Escherichia coli K-12, polAl(-) is a mutant strain whose extracts are deficient in Kornberg deoxyribonucleic acid (DNA) polymerase activity. We have compared the mutant and parental strains on the basis of a number of responses to ultraviolet (UV) and X-irradiation. For both types of radiation, the mutant is more sens...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.107.1.61-67.1971
更新日期:1971-07-01 00:00:00
abstract::We have sequenced the rightmost 1,700 base pairs of bacteriophage PRD1. This region encompasses the right early region and completes the sequence of all PRD1 early functions. We have also mapped the 5' initiation site of right early transcripts in vivo and in vitro. This has allowed us to assign gene XII to an open re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.4.1889-1898.1990
更新日期:1990-04-01 00:00:00
abstract::The genome sequence of the enteric bacterial pathogen Campylobacter jejuni NCTC 11168 (11168-GS) was published in 2000, providing a valuable resource for the identification of C. jejuni-specific colonization and virulence factors. Surprisingly, the 11168-GS clone was subsequently found to colonize 1-day-old chicks fol...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.2.503-517.2004
更新日期:2004-01-01 00:00:00
abstract::Sinorhizobium meliloti, a gram-negative soil bacterium, forms a nitrogen-fixing symbiotic relationship with members of the legume family. To facilitate our studies of transcription in S. meliloti, we cloned and characterized the gene for the alpha subunit of RNA polymerase (RNAP). S. meliloti rpoA encodes a 336-amino-...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.14.3808-3814.2002
更新日期:2002-07-01 00:00:00
abstract::In order to examine the potential role of bacterial collagenases in periodontal tissue destruction, we recently isolated a gene, prtC, from Porphyromonas gingivalis ATCC 53977, which expressed collagenase activity (N. Takahashi, T. Kato, and H. K. Kuramitsu, FEMS Microbiol. Lett. 84:135-138, 1991). The nucleotide sequ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.12.3889-3895.1992
更新日期:1992-06-01 00:00:00
abstract::Ribonucleotide reductases (RNRs) are crucial to all living cells, since they provide deoxyribonucleotides (dNTPs) for DNA synthesis and repair. In Mycobacterium tuberculosis, a class Ib RNR comprising nrdE- and nrdF2-encoded subunits is essential for growth in vitro. Interestingly, the genome of this obligate human pa...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01409-08
更新日期:2009-02-01 00:00:00