title: FimZ binds the Salmonella typhimurium fimA promoter region and may regulate its own expression with FimY.
abstract: The FimZ protein, an activator of FimA production in Salmonella typhimurium, acts in conjunction with FimY to facilitate the expression of type 1 fimbriae. The predicted amino acid sequence of FimZ suggests that this protein may be a DNA-binding protein related to BvgA, a sensory regulator of virulence gene expression in Bordetella pertussis. Purification of FimZ following overexpression of the protein by a strong inducible promoter and gel mobility shift assays confirm that FimZ is a 25-kDa polypeptide that binds to the promoter region offimA. The region of DNA protected from DNase I digestion by FimZ binding is located between 47 and 98 nucleotides upstream from thefimA transcription initiation site. This region possesses a pair of 7-base pair tandem repeats, of which at least one is necessary for FimZ binding. One copy of the 7-base pair sequence is also located in thefimZ promoter region. In addition, expression from afimZ-lacZ reporter construct confirms that FimZ plays a role in its own expression. Both FimZ and FimY are required for high-level expression of FimZ, which suggests that these two fimbrial proteins are involved in regulating both FimA and FimZ.
authors.affiliation: Department of Pathobiology, Pig Research Institute Taiwan, Chunan, Miaoli. ca@mail.prit.org.tw
authors.forename: Kuang-Sheng
authors.initials: KS
authors.lastname: Yeh
authors.forename: Juliette K
authors.initials: JK
authors.lastname: Tinker
authors.forename: Steven
authors.initials: S
authors.lastname: Clegg
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D007763:Lac Operon; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C409568:fimbriae Y protein, Salmonella; C063055:fimbrillin; C069285:fimZ protein, Bacteroides nodosus; D036781:Fimbriae Proteins