Abstract:
:The O antigen is the outer part of the lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria and contains many repeats of an oligosaccharide unit. It contributes to antigenic variability and is essential to the full function and virulence of bacteria. Shigella is a Gram-negative human pathogen that causes diarrhea in humans. The O antigen of Shigella boydii type 14 consists of repeating oligosaccharide units with the structure [→6-d-Galpα1→4-d-GlcpAβ1→6-d-Galpβ1→4-d-Galpβ1→4-d-GlcpNAcβ1→]n. The wfeD gene in the O-antigen gene cluster of Shigella boydii type 14 was proposed to encode a galactosyltransferase (GalT) involved in O-antigen synthesis. We confirmed here that the wfeD gene product is a β4-GalT that synthesizes the Galβ1-4GlcNAcα-R linkage. WfeD was expressed in Escherichia coli, and the activity was characterized by using UDP-[³H]Gal as the donor substrate as well as the synthetic acceptor substrate GlcNAcα-pyrophosphate-(CH₂)₁₁-O-phenyl. The enzyme product was analyzed by liquid chromatography-mass spectrometry (LC-MS), high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR), and galactosidase digestion. The enzyme was shown to be specific for the UDP-Gal donor substrate and required pyrophosphate in the acceptor substrate. Divalent metal ions such as Mn²(+), Ni²(+), and, surprisingly, also Pb²(+) enhanced the enzyme activity. Mutational analysis showed that the Glu101 residue within a DxD motif is essential for activity, possibly by forming the catalytic nucleophile. The Lys211 residue was also shown to be required for activity and may be involved in the binding of the negatively charged acceptor substrate. Our study revealed that the β4-GalT WfeD is a novel enzyme that has virtually no sequence similarity to mammalian β4-GalT, although it catalyzes a similar reaction.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Xu C,Liu B,Hu B,Han Y,Feng L,Allingham JS,Szarek WA,Wang L,Brockhausen Idoi
10.1128/JB.00737-10subject
Has Abstractpub_date
2011-01-01 00:00:00pages
449-59issue
2eissn
0021-9193issn
1098-5530pii
JB.00737-10journal_volume
193pub_type
杂志文章abstract::The vir-type IV secretion system of Agrobacterium is assembled from 12 proteins encoded by the virB operon and virD4. VirB1 is one of the least-studied proteins encoded by the virB operon. Its N terminus is a lytic transglycosylase. The C-terminal third of the protein, VirB1*, is cleaved from VirB1 and secreted to the...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00480-07
更新日期:2007-09-01 00:00:00
abstract::The secondary metabolite hydrogen cyanide (HCN) is produced by Pseudomonas fluorescens from glycine, essentially under microaerophilic conditions. The genetic basis of HCN synthesis in P. fluorescens CHA0 was investigated. The contiguous structural genes hcnABC encoding HCN synthase were expressed from the T7 promoter...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.12.3187-3196.1998
更新日期:1998-06-01 00:00:00
abstract::Dinitrogenase reductase-activating glycohydrolase (DRAG), involved in the regulation of nitrogenase activity in Rhodospirillum rubrum, is associated with chromatophore membranes in cell extracts. We show that DRAG can be specifically released by treatment with MgGDP; other nucleotides studied had no effect. The DRAG a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.24.7872-7874.1997
更新日期:1997-12-01 00:00:00
abstract::When titanium(III) citrate was used as electron donor for the reduction of methyl coenzyme M by the methyl coenzyme M methylreductase system of Methanobacterium thermoautotrophicum delta H, component A1 was no longer required. The simpler system thus obtained required components A2, A3, and C as well as catalytic amou...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.9.3946-3952.1988
更新日期:1988-09-01 00:00:00
abstract::Isolated sheaths of Leptothrix discophora SP-6 (ATCC 51168) were tested for susceptibility to degradation by a variety of chemical denaturants and lytic enzymes and found to be resistant to many reagents and enzyme treatments. However, disulfide bond-reducing agents such as dithiothreitol (DTT), beta-mercaptoethanol, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.24.7819-7827.1993
更新日期:1993-12-01 00:00:00
abstract::A spontaneous lac+ revertant of an adenylate cyclase deletion strain of Escherichia coli K-12 was isolated and characterized. This revertant, designated strain KC20, exhibited a pleiotropic suppression of the adenylate cyclase defect, with the crp locus being the site of the suppressor mutation. Cyclic adenosine 3',5'...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.147.2.500-508.1981
更新日期:1981-08-01 00:00:00
abstract::Upon induction, Bacillus megaterium 216 produces the bacteriocin megacin A-216, which leads to lysis of the producer cell and kills B. megaterium and a few other bacterial species. The DNA region responsible for megacinogeny was cloned in B. megaterium. The nucleotide sequence of a 5,494-bp-long subfragment was determ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00557-08
更新日期:2008-10-01 00:00:00
abstract::The effect of motility on the competitive success of Rhizobium meliloti in nodule production was investigated. A motile strain formed more nodules than expected when mixed at various unfavorable ratios with either flagellated or nonflagellated nonmotile derivatives. We conclude that motility confers a selective advant...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.148.2.728-729.1981
更新日期:1981-11-01 00:00:00
abstract::Ureolytic clinical isolates of Providencia stuartii, Salmonella spp., and some Escherichia coli strains contain large urease-encoding plasmids. Expression of urease activity from these isolates is induced at least 20-fold by urea. In order to facilitate studies on the regulatory mechanism controlling this urea-inducib...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.11.3459-3467.1993
更新日期:1993-06-01 00:00:00
abstract::The structural properties required for the binding of peptide substrates to the Escherichia coli periplasmic protein involved in oligopeptide transport were surveyed by measuring the ability of different peptides to compete for binding in an equilibrium dialysis assay with the tripeptide Ala-Phe-[3H]Gly. The protein s...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.168.2.775-779.1986
更新日期:1986-11-01 00:00:00
abstract::Bacillus thuringiensis subsp. aizawai EG6346, a novel grain dust isolate, was analyzed by Southern blot hybridization for its insecticidal crystal protein (ICP) gene profile. Strain EG6346 lacks previously characterized cryIA ICP genes yet does possess novel cryI-related gene sequences. A recombinant genomic plasmid l...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.13.3966-3976.1991
更新日期:1991-07-01 00:00:00
abstract::The temperature-sensitive cyr1-2 mutant in Saccharomyces cerevisiae produces low levels of adenylate cyclase and cyclic AMP at 25 degrees C and is unable to synthesize repressible acid phosphatase at 25 degrees C. Suppressor mutants of cyr1-2 were isolated by detecting acid phosphatase activity. One of the dominant su...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.7.2406-2408.1991
更新日期:1991-04-01 00:00:00
abstract::Acholeplasma laidlawii cells grown with oleic acid produced much more colored carotenoids than did cells grown with elaidic acid. The amount of carotenoids was decreased 80 to 90% by growing the cells with 0.05 M propionate, resulting in a marked increase in the mobility of both 5-doxylstearate and 12-doxylstearate in...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.140.3.944-948.1979
更新日期:1979-12-01 00:00:00
abstract::The gene coding for the metabolically stable 6S RNA of Escherichia coli has been cloned, sequenced, and partially characterized in expression analyses. The DNA sequence results confirm the accuracy of the previously established RNA sequence and, with genomic hybridization data, reveal that there is only one copy of th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.3.1162-1170.1985
更新日期:1985-03-01 00:00:00
abstract::Synthetic analogs of enterochelin (enterobactin) were tested for their ability to support the growth of Escherichia coli K-12 under iron-limiting conditions. The cyclic compound MECAM [1,3,5-N.N'; N"-tris-(2,3-dihydroxybenzoyl)-triamino-methylbenzene] and its N-methyl derivative Me3MECAM promoted growth, whereas the 2...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.153.1.109-115.1983
更新日期:1983-01-01 00:00:00
abstract::Bifidobacterium breve is an actinobacterium frequently isolated from colonic microbiota of breastfeeding babies. Here, we report the complete and annotated genome sequence of a B. breve strain isolated from human milk, B. breve CECT 7263. The genome sequence will provide new insights into the biology of this potential...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00691-12
更新日期:2012-07-01 00:00:00
abstract::Structural studies were carried out on lipoteichoic acids obtained from defatted cells of 10 Bacillus strains by phenol-water partition followed by chromatography on DEAE-Sephacel and Octyl-Sepharose columns. A group of the tested bacteria (group A), Bacillus subtilis, Bacillus licheniformis, and Bacillus pumilus, was...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.167.2.508-516.1986
更新日期:1986-08-01 00:00:00
abstract::The metE gene of Salmonella typhimurium was cloned into plasmid pACYC184 by using a lambda gt7 -metE transducing phage as a source of metE DNA. The recombinant plasmid, designated pGS41 , carries a 12.8-kilobase-pair EcoRI insert fragment. The metE gene was subcloned from pGS41 into plasmid pBR322 on a 4.2-kilobase-pa...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.158.3.928-933.1984
更新日期:1984-06-01 00:00:00
abstract::The ompA gene of Escherichia coli codes for a major protein of the outer membrane. When this gene was moved between various unrelated strains (E. coli K-12 and two clinical isolates of E. coli) by transduction, the gene was expressed very poorly. Recombinants carrying "foreign" genes produced no OmpA protein which cou...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.143.1.403-410.1980
更新日期:1980-07-01 00:00:00
abstract::Klebsiella pneumoniae is a nosocomial pathogen frequently isolated from opportunistic infections, especially in clinical environments. In spite of its potential pathogenicity, this microorganism has several metabolic potentials that could be used in biotechnology applications. K. pneumoniae is able to metabolize glyce...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01077-08
更新日期:2009-02-01 00:00:00
abstract::Two types of mutants unable to excrete hemolysin were obtained when E. coli 5K carrying the multicopy hemolytic recombinant plasmid pANN202-312 was mutagenized with Mu d1. One type is altered in the plasmid hly-specific gene, hlyBb, but the other is caused by an insertion of Mu d1 into a chromosomal locus. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.159.3.1083-1085.1984
更新日期:1984-09-01 00:00:00
abstract::Quorum sensing is involved in the regulation of multicellular behavior through communication via small molecules. Given the high number and diversity of the gastrointestinal microbiota, it is postulated that members of this community communicate to coordinate a variety of adaptive processes. AI-2 is suggested to be a ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01394-06
更新日期:2007-02-01 00:00:00
abstract::Cells of Pseudomonas aeruginosa resistant to benzalkonium chloride (BC) underwent unique ultrastructural reorganizations when they were grown in the presence of 1 mg of BC/ml. The resistant cells usually contained a single, centrally positioned pseudovacuole. The pseudovacuole was surrounded by a diffuse substance tha...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.113.1.409-416.1973
更新日期:1973-01-01 00:00:00
abstract::For the pathogenic yeast Candida albicans, secreted aspartyl proteinase (Sap) activity has been correlated with virulence. A family consisting of at least eight SAP genes can be drawn upon to produce Sap enzymatic activity. In this study, the levels of Sap1, Sap2, and Sap3 isoenzymes were monitored under a variety of ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.18.5215-5221.1995
更新日期:1995-09-01 00:00:00
abstract::Chloroflexus, a newly described genus of filamentous, photosynthetic, gliding bacteria, oxidizes sulfide anaerobically under photoautotrophic or photoheterotrophic growh conditions and deposits elemental sulfur outside the cell. The formation of sulfur granules outside the cell supports the idea that this organism is ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.122.2.782-784.1975
更新日期:1975-05-01 00:00:00
abstract::The ribosome content was markedly reduced when illumination (at 28 C) was repeatedly interrupted; an opposite trend was observed with continuous light as the temperature was decreased. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.97.3.1518-1519.1969
更新日期:1969-03-01 00:00:00
abstract::Berry, L. Joe (Bryn Mawr College, Bryn Mawr, Pa.), Dorothy S. Smythe, and Louise S. Colwell. Inhibition of inducible liver enzymes by endotoxin and actinomycin D. J. Bacteriol. 92:107-115. 1966.-Bacterial endotoxin at the ld(50) level lowers liver tryptophan pyrrolase in mice, it prevents for 16 to 20 hr the induction...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.92.1.107-115.1966
更新日期:1966-07-01 00:00:00
abstract::ermC specifies an rRNA methyltransferase that confers resistance to erythromycin. The expression of this determinant is induced by the addition of erythromycin. The induction mechanism has been shown to operate posttranscriptionally, and its mechanism has been elucidated. We now show that synthesis of the ermC gene pr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.168.3.1133-1141.1986
更新日期:1986-12-01 00:00:00
abstract::Monobromoacetate (MBA) is toxic for the 1,2-dichloroethane-degrading bacterium Xanthobacter autotrophicus GJ10 at concentrations higher than 5 mM. Mutants which are able to grow on higher concentrations of MBA were isolated and found to overexpress haloacid dehalogenase, which is encoded by the dhlB gene. In mutant GJ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.5.1348-1356.1995
更新日期:1995-03-01 00:00:00
abstract::The nucleoids in Mycoplasma capricolum cells were visualized by phase-combined fluorescence microscopy of DAPI (4', 6-diamidino-2-phenylindole)-stained cells. Most growing cells in a rich medium had one or two nucleoids in a cell, and no anucleate cells were found. The nucleoids were positioned in the center in mononu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.19.6073-6080.1999
更新日期:1999-10-01 00:00:00