Abstract:
:HlyD, a member of the membrane fusion protein family, is essential for the secretion of the RTX hemolytic toxin HlyA from Escherichia coli. Random point mutations affecting HlyA secretion were obtained, distributed in most periplasmic regions of the HlyD molecule. Analysis of the secretion phenotypes of different mutants allowed the identification of regions in HlyD involved in different steps of HlyA translocation. Four mutants, V349-I, T85-I, V334-I and L165-Q, were conditionally defective, a phenotype shown to be linked to the presence of inhibitory concentrations of Ca2+ in extracellular medium. Hly mutant T85-I was defective at an early stage in secretion, while mutants V334-I and L165-Q appeared to accumulate HlyA in the cell envelope, indicating a block at an intermediate step. Mutants V349-I, V334-I, and L165-Q were only partially defective in secretion, allowing significant levels of HlyA to be transported, but in the case of V349-I and L165-Q the HlyA molecules secreted showed greatly reduced hemolytic activity. Hemolysin molecules secreted from V349-I and V334-I are defective in normal folding and can be reactivated in vitro to the same levels as HlyA secreted from the wild-type translocator. Both V349-I and V334-I mutations mapped to the C-terminal lipoyl repeat motif, involved in the switching from the helical hairpin to the extended form of HlyD during assembly of the functional transport channel. These results suggest that HlyD is an integral component of the transport pathway, whose integrity is essential for the final folding of secreted HlyA into its active form.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Pimenta AL,Racher K,Jamieson L,Blight MA,Holland IBdoi
10.1128/JB.187.21.7471-7480.2005keywords:
subject
Has Abstractpub_date
2005-11-01 00:00:00pages
7471-80issue
21eissn
0021-9193issn
1098-5530pii
187/21/7471journal_volume
187pub_type
杂志文章abstract::The seven proteins encoded by the comG operon of Bacillus subtilis exhibit similarity to gene products required for the assembly of type 4 pili and for the secretion of certain proteins in gram-negative bacteria. Although polar transposon insertions in comG result in the loss of transformability and in the failure of ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.1.41-45.1998
更新日期:1998-01-01 00:00:00
abstract::Day, L. E. (Chas. Pfizer & Co., Inc., Groton, Conn.). Tetracycline inhibition of cell-free protein synthesis. II. Effect of the binding of tetracycline to the components of the system. J. Bacteriol. 92:197-203. 1966.-When tetracycline, an inhibitor of cell-free protein synthesis, was preincubated with each component o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.92.1.197-203.1966
更新日期:1966-07-01 00:00:00
abstract:UNLABELLED:The gene encoding a nonoxidative decarboxylase capable of catalyzing the transformation of 2-hydroxy-1-naphthoic acid (2H1NA) to 2-naphthol was identified, recombinantly expressed, and purified to homogeneity. The putative gene sequence of the decarboxylase (hndA) encodes a 316-amino-acid protein (HndA) with...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00250-16
更新日期:2016-05-27 00:00:00
abstract::Certain mutations in the C-terminal region of the Escherichia coli division inhibitor protein MinC cause loss of function of the division inhibitor by making MinC more sensitive to degradation by Lon protease, implying a possible role for the C-terminal region in regulating the stability and cellular concentration of ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.1.175-177.1998
更新日期:1998-01-01 00:00:00
abstract:UNLABELLED:All methanofuran structural variants contain a basic core structure of 4-[N-(γ-l-glutamyl)-p-(β-aminoethyl)phenoxymethyl]-(aminomethyl)furan (APMF-Glu) but have different side chains depending on the source organism. Recently, we identified four genes (MfnA, MfnB, MfnC, and MfnD) that are responsible for the...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00401-15
更新日期:2015-09-01 00:00:00
abstract::Cultures of the inducible penicillinase-producing strain 749 of Bacillus licheniformis, induced with small amounts of benzylpenicillin, synthesized penicillinase at a high rate for a short period, after which the rate of synthesis slowly declined. During the period of active synthesis, the rate of secretion, as a frac...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.97.2.820-826.1969
更新日期:1969-02-01 00:00:00
abstract::Scanning electron microscopy and transmission electron microscopy have been used to visualize the morphology and ultrastructure of two types of microorganisms in the hindgut of the cockroach Blaberus posticus. Both organisms, designated as either short or long rods, are attached to chitinous projections from the gut w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.123.1.336-345.1975
更新日期:1975-07-01 00:00:00
abstract::Salmonella typhimurium LT2 normally expresses two acetohydroxy acid synthases (AHAS I and AHAS II). The function of AHAS I in this organism was unclear, since AHAS I-deficient (ilvBN) mutants of LT2 grew well on glucose or succinate minimal media, whereas AHAS II-deficient (ilvGM) mutants requried isoleucine for norma...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.2.917-919.1987
更新日期:1987-02-01 00:00:00
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 a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.19.5612-5621.1995
更新日期:1995-10-01 00:00:00
abstract::Crystalline inclusions occur in bacterium 22M. Arrays consist of parallel rows of polyhedral subunits (7.5 nm in diameter), 2.0 nm apart, with a distance of 3.0 nm between rows. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.98.3.1390-1394.1969
更新日期:1969-06-01 00:00:00
abstract::The relationship between the levels of cyclic nucleotides and dimorphic transition in Candida albicans was examined. The results showed that cells of this pathogenic fungus contained both cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-monophosphate (cGMP), the concentration of the latter being ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.142.3.1010-1014.1980
更新日期:1980-06-01 00:00:00
abstract::Escherichia coli ssrA encodes a small stable RNA molecule, tmRNA, that has many diverse functions, including tagging abnormal proteins for degradation, supporting phage growth, and modulating the activity of DNA binding proteins. Here we show that ssrA plays a role in Salmonella enterica serovar Typhimurium pathogenes...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.6.1558-1563.2000
更新日期:2000-03-01 00:00:00
abstract::The yfdXWUVE operon appears to encode proteins that enhance the ability of Escherichia coli MG1655 to survive under acidic conditions. Although the molecular mechanisms underlying this phenotypic behavior remain to be elucidated, findings from structural genomic studies have shown that the structure of YfdW, the prote...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01823-07
更新日期:2008-04-01 00:00:00
abstract::Two genes, xylP and xylQ, from the xylose regulon of Lactobacillus pentosus were cloned and sequenced. Together with the repressor gene of the regulon, xylR, the xylPQ genes form an operon which is inducible by xylose and which is transcribed from a promoter located 145 bp upstream of xylP. A putative xylR binding sit...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.9.2312-2320.1998
更新日期:1998-05-01 00:00:00
abstract::Bacitracin is a peptide antibiotic nonribosomally produced by Bacillus licheniformis. The bcrABC genes which confer bacitracin resistance to the bacitracin producer encode ATP binding cassette (ABC) transporter proteins, which are hypothesized to pump out bacitracin from the cells. Bacillus subtilis 168, which has no ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.1.51-59.2003
更新日期:2003-01-01 00:00:00
abstract::The role of the proton gradient and external pH in the motility and chemotaxis of Bacillus subtilis was investigated. Presence of a substantial proton gradient is not necessary for motility or chemotaxis, as long as the electrical potential is sufficient to maintain motility. Changes in the proton gradient do, however...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.141.1.26-32.1980
更新日期:1980-01-01 00:00:00
abstract::The Escherichia coli K-12 hisT gene has been cloned, and its organization and expression have been analyzed on multicopy plasmids. The hisT gene, which encodes tRNA pseudouridine synthase I (PSUI), was isolated on a Clarke-Carbon plasmid known to contain the purF gene. The presence of the hisT gene on this plasmid was...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.1.60-71.1985
更新日期:1985-01-01 00:00:00
abstract::Evidence of the presence of messenger ribonucleic acid (mRNA) in dormant spores of Bacillus subtilis has been obtained. The bulk RNA from spores was isolated and labeled in vitro with tritiated dimethyl sulfate. The spore RNA hybridized to 2.4 to 3.2% of the B. subtilis genome. The RNA hybridized to both the complemen...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.119.2.514-521.1974
更新日期:1974-08-01 00:00:00
abstract::Cultures of recombination-deficient strains of Escherichia coli are composed of three classes of cells: (i) viable cells, which can undergo 20 or more generations, (ii) residually dividing cells, which can undergo fewer than 20 generations (probably an average of fewer than 6), and (iii) nondividing cells, which are i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.1.242-249.1974
更新日期:1974-04-01 00:00:00
abstract::Expression of fimA, the structural gene for type 1 fimbriae of Escherichia coli, is phase variable. Significant homologies were identified between the recombinases which control fimbrial phase variation, FimB and FimE, and the integrase class of site-specific recombinases. Normal expression of fimA was shown to requir...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3840-3843.1987
更新日期:1987-08-01 00:00:00
abstract::Plasmid R1 is a low-copy-number plasmid that is present at a level of about four or five copies per average cell. The copy number is controlled posttranscriptionally at the level of synthesis of the rate-limiting initiator protein RepA. In addition to this, R1 has an auxiliary system that derepresses a second promoter...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.1.207-211.2004
更新日期:2004-01-01 00:00:00
abstract::Gill lamellae from the young fruiting bodies of the basidiomycete Coprinus micaceus possess cytoplasmic particles with cytochemically demonstrable acid phosphatase activity; they are presumed to be lysosomes. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.115.1.443-446.1973
更新日期:1973-07-01 00:00:00
abstract::Of 20 clinical isolates of Haemophilus parainfluenzae, 13 produced a mannose-resistant hemagglutinin that agglutinated erythrocytes from chickens, horses, rabbits, and sheep. Examination with the electron microscope showed that only strain HR-885 was pilate. Grown in static liquid culture, the 12 hemagglutinating, non...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.145.2.1075-1078.1981
更新日期:1981-02-01 00:00:00
abstract::TolB is a periplasmic protein of the cell envelope Tol complex. It is partially membrane associated through an interaction with the outer membrane lipoprotein PAL (peptidoglycan-associated lipoprotein), which also belongs to the Tol system. The interaction of TolB with outer membrane porins of Escherichia coli was inv...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.23.7274-7279.1997
更新日期:1997-12-01 00:00:00
abstract::Escherichia coli K-12 produces at least two ATP-dependent proteases, Lon (La) and Clp (Ti), the latter consisting of a regulatory subunit (ClpA) and a proteolytic subunit (ClpP). The gene clpB encoding an analog of ClpA had been found at 57 min on the E. coli chromosome. Cloning and examination of novel heat shock pro...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.14.4247-4253.1991
更新日期:1991-07-01 00:00:00
abstract::Enteric pathogens have developed several resistance mechanisms to survive the antimicrobial action of bile. We investigated the transcriptional profile of Vibrio cholerae O1 El Tor strain C6706 under virulence gene-inducing conditions in the presence and absence of bile. Microarray analysis revealed that the expressio...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00584-08
更新日期:2008-11-01 00:00:00
abstract::YoeB is a bacterial toxin encoded by the yefM-yoeB toxin-antitoxin system found in various bacterial genomes. Here, we show that Staphylococcus aureus contains two YoeB homologues, both of which function as ribosome-dependent mRNA interferases to inhibit translation initiation in a manner identical to that of YoeB-ec ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00623-09
更新日期:2009-09-01 00:00:00
abstract::Vibrio cholerae, the causative agent of the human diarrheal disease cholera, is a motile bacterium with a single polar flagellum. Motility has been implicated as a virulence determinant in some animal models of cholera, but the relationship between motility and virulence has not yet been clearly defined. We have begun...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.2.303-316.1998
更新日期:1998-01-01 00:00:00
abstract::Growth rate control of adherent, sessile populations was achieved by the controlled perfusion of membrane-associated bacterial biofilms by the method of Gilbert et al. (P. Gilbert, D. G. Allison, D. J. Evans, P. S. Handley, and M. R. W. Brown, Appl. Environ. Microbiol. 55:1308-1311, 1989). Changes in cell surface hydr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.3.1667-1669.1990
更新日期:1990-03-01 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