title: Activation and repression at the Escherichia coli ynfEFGHI operon promoter.
abstract: Induction of the Escherichia coli K-12 ynfEFGHI operon in response to anaerobiosis is repressed by nitrate ions. In this study, we show that the global transcription factor FNR is a class II activator at the ynfEFGHI promoter and that NarL represses activation by binding to a single target that overlaps the promoter -10 element. Electromobility shift assays show that NarL does not prevent RNA polymerase binding and suggest that repression may involve a quaternary NarL-FNR-RNA polymerase-promoter complex.
authors.affiliation: School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom.
authors.forename: Meng
authors.initials: M
authors.lastname: Xu
authors.forename: Stephen J W
authors.initials: SJ
authors.lastname: Busby
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Browning
mesh_terms: D000693:Anaerobiosis; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000502:physiology*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D048168:Escherichia coli K12 / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D007506:Iron-Sulfur Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015533:Transcriptional Activation
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; C069780:NarL protein, E coli; D012321:DNA-Directed RNA Polymerases