title: The hexY genes of Erwinia carotovora ssp. carotovora and ssp. atroseptica encode novel proteins that regulate virulence and motility co-ordinately.
abstract: Mutations located in a new gene, hexY, in Erwinia carotovora ssp. carotovora (Ecc) and ssp. atroseptica (Eca) cause strong upregulation of production of exoenzyme virulence factors and motility. The hexY gene encodes a novel 14.4 kDa protein with no known homologues. The hexY mRNA transcript has an unusually long (525bp) 5' untranslated region, which may be important for post-transcriptional regulation. An elevated level of transcription of two exoenzyme genes, pelCand celV, was observed in the HexY mutant background. The levels of cellulase and protease in a HexY mutant were independent of the presence of PGA, suggesting a role for HexY in the induction of these enzymes seen upon PGA addition. Electron microscopy revealed that HexY cells were hyperflagellated, perhaps contributing to the hypermotility phenotype of this mutant. The HexY mutant M5 exhibited enhanced maceration capacity on potato tubers. Therefore, the hexY gene and its gene product may define another level of regulation of virulence determinants in Ecc and Eca.
authors.affiliation: Department of Biochemistry, University of Cambridge, UK.
authors.forename: Y L
authors.initials: YL
authors.lastname: Shih
authors.forename: S J
authors.initials: SJ
authors.lastname: Harris
authors.forename: G
authors.initials: G
authors.lastname: Borner
authors.forename: M M
authors.initials: MM
authors.lastname: Rivet
authors.forename: G P
authors.initials: GP
authors.lastname: Salmond
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002480:Cellulase / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D016973:Pectobacterium carotovorum / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D011133:Polysaccharide-Lyases / Q000235:genetics; D011198:Solanum tuberosum / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D007527:Isoenzymes; C427443:hexY protein, Erwinia carotovora; C084311:CelV protein, Erwinia carotovora; D002480:Cellulase; D011133:Polysaccharide-Lyases; C023911:pectate lyase