title: Genetic and molecular analysis of a cluster of rpf genes involved in positive regulation of synthesis of extracellular enzymes and polysaccharide in Xanthomonas campestris pathovar campestris.
abstract: The cosmid clone pIJ3020 containing DNA from the plant pathogenic bacterium Xanthomonas campestris pathovar campestris has previously been shown to complement a non-pathogenic mutant defective in synthesis of extracellular enzymes. The DNA cloned in pIJ3020 was analysed by mutagenesis with Tn5 and Tn5lac and by nucleotide sequencing. The results indicate that this region of the genome contains a cluster of genes, mutation in any of which results in failure of the enzymes and extracellular polysaccharide to be synthesized. The designation rpf (regulation of pathogenicity factors) is proposed for these genes. The nucleotide sequence of one gene (rpfC) predicts a protein product with homology to conserved domains of both sensor and regulator proteins of prokaryotic two-component regulatory systems, which are usually involved in regulating gene expression in response to environmental stimuli.
authors.affiliation: Sainsbury Laboratory, John Innes Centre for Plant Science Research, Norwich, UK.
authors.forename: J L
authors.initials: JL
authors.lastname: Tang
authors.forename: Y N
authors.initials: YN
authors.lastname: Liu
authors.forename: C E
authors.initials: CE
authors.lastname: Barber
authors.forename: J M
authors.initials: JM
authors.lastname: Dow
authors.forename: J C
authors.initials: JC
authors.lastname: Wootton
authors.forename: M J
authors.initials: MJ
authors.lastname: Daniels
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics*; D004798:Enzymes / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D011134:Polysaccharides / Q000096:biosynthesis*; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D014974:Xanthomonas / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004798:Enzymes; D011134:Polysaccharides