Abstract:
:Enteroaggregative Escherichia coli (EAggEC) has been associated with persistent pediatric diarrhea in the developing world, yet the pathogenetic mechanisms of EAggEC infection are unknown. Our previous data have suggested that aggregative adherence of some EAggEC strains to HEp-2 cells is mediated by flexible, bundle-forming fimbriae, which we have termed aggregative adherence fimbriae I (AAF/I). Genes sufficient to confer expression of AAF/I are located on the 60-MDa plasmid of EAggEC 17-2; AAF/I genes are present as two unlinked plasmid regions (regions 1 and 2), separated by 9 kb of DNA. Here we report the complete DNA sequencing of region 2 and the identification of an open reading frame which is involved in the expression of AAF/I. One open reading frame of 794 bp encodes a protein (designated AggR) with a predicted molecular size of 29.4 kDa, which shows a high degree of amino acid sequence identity to CfaR and other members of the AraC class of gene regulators. The cloned aggR gene (or, alternatively, a cloned cfaR gene) was sufficient to complement a region 1 clone to confer AAF/I expression. To further substantiate the role of aggR in the regulation of AAF/I, we constructed a 289-bp in-frame aggR deletion and replaced the native gene in 17-2 by allelic exchange, using the temperature-sensitive vector pIB307. The resulting aggR deletions were negative for AAF/I expression, but expression was restored when the aggR gene (cloned into pBluescript II SK) was reintroduced into the aggR mutant. RNA slot blot experiments using a probe for the putative AAF/I pilin subunit (aggA) revealed that aggR operates as a transcriptional activator of aggA expression. aggA::phoA fusions were constructed in 17-2 and in 17-2 delta aggR. AggR was found to promote expression of the aggA gene under a variety of conditions of temperature, osmolarity, oxygen tension, and medium. At acid pH, aggA expression was maximal and was regulated by both AggR-dependent and AggR-independent mechanisms.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Nataro JP,Yikang D,Yingkang D,Walker Kdoi
10.1128/jb.176.15.4691-4699.1994subject
Has Abstractpub_date
1994-08-01 00:00:00pages
4691-9issue
15eissn
0021-9193issn
1098-5530journal_volume
176pub_type
杂志文章abstract::A technique for identifying and characterizing staphylococcal hemolysins by first separating them electrophoretically in barbital-buffered agar gel (pH 8.4) at 5 ma/cm for 2 hr and then determining their hemolytic activities by exposing them to human, horse, rabbit, and sheep erythrocytes is described. The alpha-hemol...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.93.2.525-530.1967
更新日期:1967-02-01 00:00:00
abstract::Site-specific mutagenesis has identified amino acids involved in bR proton transport. Biophysical studies of the mutants have elucidated the roles of two membrane-embedded residues: Asp-85 serves as the acceptor for the proton from the isomerized retinylidene Schiff base, and Asp-96 participates in reprotonation of th...
journal_title:Journal of bacteriology
pub_type: 杂志文章,评审
doi:10.1128/jb.175.6.1555-1560.1993
更新日期:1993-03-01 00:00:00
abstract::The expression of R-factor-mediated resistance to tetracycline has been compared in Proteus mirabilis and Escherichia coli. Resistance to a range of concentrations of tetracycline was significantly lower in P. mirabilis than in E. coli in both induced and repressed states. Indirect evidence showed that conditions whic...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.115.1.235-242.1973
更新日期:1973-07-01 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::We have isolated transposon insertions in the lacA gene encoding an endogenous beta-galactosidase of Bacillus subtilis. Upstream of the putative operon containing lacA is a negative regulator, lacR, which encodes a product related to a family of regulators that includes the lactose repressor, lacI, of Escherichia coli...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.17.5636-5638.1997
更新日期:1997-09-01 00:00:00
abstract::Expression of the lower catabolic pathway of the TOL plasmid pWWO requires an aromatic acid inducer and the product of the xylS regulatory gene. Pseudomonas putida cells transformed with a plasmid containing the operator-promoter region of the lower pathway (OP2 [or Pm]), upstream from the catechol 2,3-dioxygenase str...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.8.3742-3746.1988
更新日期:1988-08-01 00:00:00
abstract::Haight, Rodger D. (Oregon State University, Corvallis), and Richard Y. Morita. Thermally induced leakage from Vibrio marinus, an obligately psychrophilic bacterium. J. Bacteriol. 92:1388-1393. 1966.-Leakage of various cellular components into the surrounding menstruum occurred when Vibrio marinus was subjected to temp...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.92.5.1388-1393.1966
更新日期:1966-11-01 00:00:00
abstract::Kimler, Alexander (National Institutes of Health, Bethesda, Md.). Fluorescein amine media for rapid differentiation of staphylococci. J. Bacteriol. 82:106-109. 1961.-By modifying conventional media to include blood, mannitol, and fluorescein amine, staphylococci may be isolated and identified directly. Staphylococcus ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.82.1.106-109.1961
更新日期:1961-07-01 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::Biogenesis of the outer membrane (OM) is an essential process in gram-negative bacteria. One of the key steps of OM biogenesis is the assembly of integral outer membrane beta-barrel proteins (OMPs) by a protein machine called the Bam complex. In Escherichia coli, the Bam complex is composed of the essential proteins B...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06426-11
更新日期:2012-03-01 00:00:00
abstract::Supplementation of the growth medium with high concentrations of NaCl, KCl, or sucrose caused a drastic change in the ratio of the two peptidoglycan-associated major outer membrane proteins of Escherichia coli K-12 in that the amounts of proteins b and c present in cell envelope preparations decreased and increased, r...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.131.2.623-630.1977
更新日期:1977-08-01 00:00:00
abstract::Overproduction of tryptophanyl-tRNA synthetase increased trp operon expression by reducing transcription termination at the trp attenuator. The total cellular level of charged tRNATrp was not affected by increased levels of the synthetase. We propose that excess synthetase binds charged tRNATrp and reduces the concent...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.160.2.805-807.1984
更新日期:1984-11-01 00:00:00
abstract::The isolation and some properties of two mutants of Streptococcus faecalis ATCC 9790 (S. faecium) which autolyze at a much slower rate than the wild type are described. Compared with the wild type, mutant E71 autolyzed more slowly, contained less active but more latent autolysin in the isolated wall fraction, and poss...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.109.1.423-431.1972
更新日期:1972-01-01 00:00:00
abstract::The levels of transfer ribonucleic acids (tRNAs) specific for 14 amino acids were almost identical in dormant spores and in spores germinated from 6 to 75 min. Germinated spore tRNAs specific for all amino acids tested were between 63 and 93% charged, and there was no significant change in this value from 6 to 75 min ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.3.1067-1074.1974
更新日期:1974-06-01 00:00:00
abstract::Surface protein antigens of Mycoplasma hyopneumoniae were identified by direct antibody-surface binding or by radioimmunoprecipitation of surface 125I-labeled proteins with a series of monoclonal antibodies (MAbs). Surface proteins p70, p65, p50, and p44 were shown to be integral membrane components by selective parti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.12.5546-5555.1987
更新日期:1987-12-01 00:00:00
abstract::The sequential morphological events in spore formation by Clostridium perfringens type D were observed in Ellner's medium where 80 to 100% of the cells formed spores. Gross structural changes were studied with the light microscope under phase-contrast, and in fixed cells by the use of both nigrosin and Giemsa preparat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.5.1818-1834.1968
更新日期:1968-11-01 00:00:00
abstract::Pyridine nucleotide-dependent glucose dehydrogenase activity (GPND) is described for the first time in cell-free extracts of certain blue-green algae. When glucose is added to these crude cell extracts, nicotinamide adenine dinucleotide phosphate is reduced at twice the rate as nicotinamide adenine dinucleotide; but e...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.114.1.28-33.1973
更新日期:1973-04-01 00:00:00
abstract::Carbon catabolite control protein A (CcpA) is the main regulator involved in carbon catabolite repression in gram-positive bacteria. Time series gene expression analyses of Lactococcus lactis MG1363 and L. lactis MG1363DeltaccpA using DNA microarrays were used to define the CcpA regulon of L. lactis. Based on a compar...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01013-06
更新日期:2007-02-01 00:00:00
abstract::In Escherichia coli cultures maximally inhibited with chloramphenicol, formation of polypeptides still continued at a slow, constant rate for at least 90 min. The rate of leucine incorporation was reduced to 0.5%, but methionine was only reduced to 2%, suggesting that chains are normally initiated with methionine but ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.2.582-589.1974
更新日期:1974-05-01 00:00:00
abstract::The DNA sequence of the central regulatory locus vir of Bordetella pertussis predicts that three gene products, BvgA, BvgB, and BvgC, are encoded. Features of the predicted primary structures of these proteins and their homology to other two-component systems suggest that BvgA is located in the cytoplasm, BvgB is loca...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.14.4288-4296.1991
更新日期:1991-07-01 00:00:00
abstract::Synchronized cultures of Anacystis nidulans (Synechococcus PCC 6301), an obligate phototroph, are obtained by incubating exponential cultures in the dark for 12 to 16 h. A temporal and sequential order of macromolecular synthesis is observed within the cell division cycle of a synchronously dividing culture in the lig...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.153.3.1315-1321.1983
更新日期:1983-03-01 00:00:00
abstract::The presence of the membrane lipid phosphatidylcholine (PC) in the bacterial membrane is critically important for many host-microbe interactions. The phospholipid N-methyltransferase PmtA from the plant pathogen Agrobacterium tumefaciens catalyzes the formation of PC by a three-step methylation of phosphatidylethanola...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01539-10
更新日期:2011-07-01 00:00:00
abstract::Pseudomonas putida KT2440 is a soil microorganism that attaches to seeds and efficiently colonizes the plant's rhizosphere. Lysine is one of the major compounds in root exudates, and P. putida KT2440 uses this amino acid as a source of carbon, nitrogen, and energy. Lysine is channeled to delta-aminovaleric acid and th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.186.11.3439-3446.2004
更新日期:2004-06-01 00:00:00
abstract::The carbon dioxide requirement of 32 strains of rumen bacteria, representing 11 different species, was studied in detail. Increasing concentrations of CO(2) were added as NaHCO(3) to a specially prepared CO(2)-free medium which was tubed and inoculated under nitrogen. Prior depletion of CO(2) in the inoculum was found...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.105.1.70-76.1971
更新日期:1971-01-01 00:00:00
abstract::The copy number of 2 mu DNA-derived plasmids in CIR+ Saccharomyces cerevisiae transformants is determined by its selective marker and is usually much lower than that of the endogenous plasmid. Only plasmids containing the leu2 allele of pJDB219, designated as leu2-d, under selective conditions displayed a higher copy ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.156.2.625-635.1983
更新日期:1983-11-01 00:00:00
abstract::In Escherichia coli anaerobic growth lowers the basal or induced levels of numerous enzymes associated with aerobic metabolism. Mutations in arcA (dye) at min 0 relieve this pleiotropic anaerobic repression and render the cell sensitive to the redox dye toluidine blue. In this study we identified a second pleiotropic ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.2.868-873.1989
更新日期:1989-02-01 00:00:00
abstract::We constructed a shuttle vector, pE5-2, which can replicate in both Bacteroides spp. and Escherichia coli. pE5-2 contains a cryptic Bacteroides plasmid (pB8-51), a 3.8-kilobase (kb) EcoRI-D fragment from the 41-kb Bacteroides fragilis plasmid pBF4, and RSF1010, an IncQ E. coli plasmid. pE5-2 was mobilized by R751, an ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.162.2.626-632.1985
更新日期:1985-05-01 00:00:00
abstract::Photobacterium leiognathi ATCC 25521 (the type strain and light-organ symbiont of ponyfish) is one of the few bacteria that produces a copper-zinc superoxide dismutase, termed bacteriocuprein. We enzymologically and immunologically characterized the bacteriocuprein superoxide dismutases in sonicates from the type stra...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.165.2.393-398.1986
更新日期:1986-02-01 00:00:00
abstract::Levy, Stuart B. (Institut du Radium, Paris, France). Isologous interference with ultraviolet and X-ray irradiated bacteriophage T(2). J. Bacteriol. 87:1330-1338. 1964.-Qualitative and quantitative analysis of the interference capacity of an irradiated T(2) bacteriophage was made with ultraviolet and X-ray irradiation....
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.87.6.1330-1338.1964
更新日期:1964-06-01 00:00:00
abstract::The marRAB operon is one of two operons in the mar locus of Escherichia coli that are divergently transcribed from a central regulatory region, marO. The marRAB operon, transcribed from marOII, controls intrinsic resistance or susceptibility to multiple antibiotics and is inducible by structurally unrelated compounds ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.12.3414-3419.1995
更新日期:1995-06-01 00:00:00