title: VpsR, a Member of the Response Regulators of the Two-Component Regulatory Systems, Is Required for Expression of vps Biosynthesis Genes and EPS(ETr)-Associated Phenotypes in Vibrio cholerae O1 El Tor.
abstract: The rugose colonial variant of Vibrio cholerae O1 El Tor produces an exopolysaccharide (EPS(ETr)) that enables the organism to form a biofilm and to resist oxidative stress and the bactericidal action of chlorine. Transposon mutagenesis of the rugose variant led to the identification of vpsR, which codes for a homologue of the NtrC subclass of response regulators. Targeted disruption of vpsR in the rugose colony genetic background yielded a nonreverting smooth-colony morphotype that produced no detectable EPS(ETr) and did not form an architecturally mature biofilm. Analysis of two genes, vpsA and vpsL, within the vps cluster of EPS(ETr) biosynthesis genes revealed that their expression is induced above basal levels in the rugose variant, compared to the smooth colonial variant, and requires vpsR. These results show that VpsR functions as a positive regulator of vpsA and vpsL and thus acts to positively regulate EPS(ETr) production and biofilm formation.
authors.affiliation: Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University Medical School, Stanford, California 94305, USA.  fitnat@cmgm.stanford.edu
authors.forename: F H
authors.initials: FH
authors.lastname: Yildiz
authors.forename: N A
authors.initials: NA
authors.lastname: Dolganov
authors.forename: G K
authors.initials: GK
authors.lastname: Schoolnik
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D018441:Biofilms / Q000254:growth & development*; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D018390:Gene Targeting; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010641:Phenotype; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D014158:Transcription, Genetic; D014734:Vibrio cholerae / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D011135:Polysaccharides, Bacterial; C422325:VpsR protein, Vibrio cholerae