title: Characterization of an ECF sigma factor protein from Pseudomonas aeruginosa.
abstract: The PvdS protein is essential for synthesis of the siderophore pyoverdine by Pseudomonas aeruginosa. PvdS has some sequence similarity to a family of alternative sigma factor proteins (the ECF [extracytoplasmic factor] family) that direct bacterial RNA polymerases to transcribe genes encoding extracytoplasmic factors. PvdS was purified as a His-tagged protein (hPvdS) and this was used to test the hypothesis that PvdS is a sigma factor protein. The purified protein caused core RNA polymerase from Escherichia coli to bind specifically to the promoters of pyoverdine synthesis genes and enabled transcription from these promoters in vitro. In addition, PvdS was found to co-purify with RNA polymerase from P. aeruginosa, indicating that PvdS associates with RNA polymerase inside the bacteria. These results show that PvdS is a sigma factor protein.
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: M J
authors.initials: MJ
authors.lastname: Wilson
authors.forename: I L
authors.initials: IL
authors.lastname: Lamont
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D009842:Oligopeptides; D010860:Pigments, Biological / Q000096:biosynthesis; D011401:Promoter Regions, Genetic; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*; D017262:Siderophores / Q000096:biosynthesis; D012808:Sigma Factor / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009842:Oligopeptides; D010860:Pigments, Biological; C093593:PvdS protein, Pseudomonas aeruginosa; D017262:Siderophores; D012808:Sigma Factor; C042453:pyoverdin; D012321:DNA-Directed RNA Polymerases