title: Integration host factor facilitates repression of the put operon in Salmonella typhimurium.
abstract: Transcriptional regulation of the put operon is mediated by a unique mechanism involving autogenous regulation by the PutA protein, a membrane-associated dehydrogenase. The 420-bp put control region contains the putP and putA promoters, multiple operator sites, multiple catabolite repression protein binding sites, and several potential integration host factor (IHF)-binding sites (ihf). In this study, we show that IHF facilitates repression of the put operon in vivo, and IHF binds specifically to two ihf sites in the put control region in vitro. DNA gyrase mutants that alter the degree of chromosomal supercoiling do not affect put regulation, indicating that the effect of IHF on put expression is in this case independent of supercoiling.
authors.affiliation: Department of Microbiology, University of Illinois, Urbana 61801.
authors.forename: K
authors.initials: K
authors.lastname: O'Brien
authors.forename: G
authors.initials: G
authors.lastname: Deno
authors.forename: P
authors.initials: P
authors.lastname: Ostrovsky de Spicer
authors.forename: J F
authors.initials: JF
authors.lastname: Gardner
authors.forename: S R
authors.initials: SR
authors.lastname: Maloy
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004794:Enzyme Repression / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009875:Operator Regions, Genetic / Q000235:genetics; D009876:Operon / Q000235:genetics*; D011392:Proline / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D012486:Salmonella typhimurium / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D034982:Integration Host Factors; C440508:integration host factor, Salmonella; D011392:Proline