title: Identification of the promoter regions and sigma(s)-dependent regulation of the gadA and gadBC genes associated with glutamate-dependent acid resistance in Shigella flexneri.
abstract: Resistance to killing by low pH is a common feature of both Escherichia coli and Shigella flexneri. The most effective E. coli acid resistance system utilizes two isoforms of glutamate decarboxylase encoded by gadA and gadB, and a putative glutamate/gamma-amino butyric acid antiporter encoded by gadC. Expression of the gad system is dependent upon the alternate sigma factor, sigma(s). We confirm that gadA, gadB, and gadC are also all dependent upon sigma(s) for their expression in S. flexneri. -10 sequences similar to the sigma(s)-10 consensus sequence were identified by primer extension in the upstream promoters of all three genes and the transcriptional start points were identical in both E. coli and S. flexneri.
authors.affiliation: Division of Human Immunology, Hanson Institute, IMVS, Adelaide, SA 5000, Australia. scott.waterman@imvs.sa.gov.au
authors.forename: Scott R
authors.initials: SR
authors.lastname: Waterman
authors.forename: P L C
authors.initials: PL
authors.lastname: Small
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005968:Glutamate Decarboxylase / Q000235:genetics; D018698:Glutamic Acid / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012763:Shigella flexneri / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D012808:Sigma Factor / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C491226:GadC protein, E coli; C103589:GadC protein, bacteria; D008565:Membrane Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D018698:Glutamic Acid; C121044:gadA protein, E coli; D005968:Glutamate Decarboxylase