title: Identification of new members of the Escherichia coli K-12 MG1655 SlyA regulon.
abstract: SlyA is a member of the MarR family of bacterial transcriptional regulators. Previously, SlyA has been shown to directly regulate only two operons in Escherichia coli K-12 MG1655, fimB and hlyE (clyA). In both cases, SlyA activates gene expression by antagonizing repression by the nucleoid-associated protein H-NS. Here, the transcript profiles of aerobic glucose-limited steady-state chemostat cultures of E. coli K-12 MG1655, slyA mutant and slyA over-expression strains are reported. The transcript profile of the slyA mutant was not significantly different from that of the parent; however, that of the slyA expression strain was significantly different from that of the vector control. Transcripts representing 27 operons were increased in abundance, whereas 3 were decreased. Of the 30 differentially regulated operons, 24 have previously been associated with sites of H-NS binding, suggesting that antagonism of H-NS repression is a common feature of SlyA-mediated transcription regulation. Direct binding of SlyA to DNA located upstream of a selection of these targets permitted the identification of new operons likely to be directly regulated by SlyA. Transcripts of four operons coding for cryptic adhesins exhibited enhanced expression, and this was consistent with enhanced biofilm formation associated with the SlyA over-producing strain.
authors.affiliation: Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Curran
authors.affiliation: Biomolecular Research Centre, Sheffield Hallam University, Sheffield, S1 1WB, UK.
authors.forename: Fatima
authors.initials: F
authors.lastname: Abacha
authors.affiliation: Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Hibberd
authors.affiliation: Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Rolfe
authors.affiliation: Biomolecular Research Centre, Sheffield Hallam University, Sheffield, S1 1WB, UK.
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Lacey
authors.affiliation: Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Green
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D004268:DNA-Binding Proteins / Q000235:genetics*; D048168:Escherichia coli K12 / Q000235:genetics* / Q000254:growth & development; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C056785:salmolysin