title: TetR family member psrA directly binds the Pseudomonas rpoS and psrA promoters.
abstract: We have previously described a Pseudomonas gene, psrA, which enhances transcription of the rpoS sigma factor gene at stationary phase. We present molecular data which demonstrate that in Pseudomonas putida PsrA binds specifically to the rpoS and psrA promoters in DNA regions having similar palindromic sequences, C/GAAAC N(2-4) GTTTG/C, where N is any nucleotide. The position of the initiation of transcription was determined for both promoters, and PsrA binds from positions -59 to -35 in the rpoS promoter and from -18 to +20 in the psrA promoter with respect to the +1 transcription site. Expression studies with a psrA-lacZ transcriptional fusion in wild-type and psrA::Tn5 knockout mutants revealed that psrA was under additional control in response to growth phase. A model for the role of PsrA in the regulation of rpoS and psrA is presented.
authors.affiliation: Bacteriology Group, International Centre for Genetic Engineering & Biotechnology, 34012 Trieste, Italy.
authors.forename: Milan
authors.initials: M
authors.lastname: Kojic
authors.forename: Claudio
authors.initials: C
authors.lastname: Aguilar
authors.forename: Vittorio
authors.initials: V
authors.lastname: Venturi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011549:Pseudomonas / Q000235:genetics*; D012808:Sigma Factor / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics* / Q000502:physiology*; D014157:Transcription Factors
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C430183:PsrA protein, Pseudomonas; D012808:Sigma Factor; D015534:Trans-Activators; D014157:Transcription Factors; C069567:sigma factor KatF protein, Bacteria