title: Xanthomonas albilineans HtpG is required for biosynthesis of the antibiotic and phytotoxin albicidin.
abstract: Xanthomonas albilineans, the causal agent of leaf scald disease of sugarcane, produces a highly potent polyketide-peptide antibiotic and phytotoxin called albicidin. Previous studies established the involvement of a large cluster of genes in the biosynthesis of this toxin. We report here the sub-cloning and sequencing of an additional gene outside of the main cluster and essential for albicidin biosynthesis. This gene encodes a 634-amino-acid protein that shows high identity with the Escherichia coli heat shock protein HtpG. Complementation studies of X. albilineans Tox- mutants confirmed the requirement of htpG for albicidin biosynthesis and revealed functional interchangeability between E. coli and X. albilineans htpG genes. HtpG was co-localised with albicidin in the cellular membrane, i.e., the cellular fraction where the toxin is most probably biosynthesised. Here we show the requirement of an HtpG protein for the biosynthesis of a polyketide-peptide antibiotic.
authors.affiliation: Centre de Coopération Internationale en Recherche Agronomique pour le Développement, UMR 385 BGPI, Campus International de Baillarguet, TA 41/K, 34398 Montpellier Cedex 5, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Vivien
authors.forename: Sandrine
authors.initials: S
authors.lastname: Megessier
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pieretti
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cociancich
authors.forename: Roger
authors.initials: R
authors.lastname: Frutos
authors.forename: Dean W
authors.initials: DW
authors.lastname: Gabriel
authors.forename: Philippe C
authors.initials: PC
authors.lastname: Rott
authors.forename: Monique
authors.initials: M
authors.lastname: Royer
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D002462:Cell Membrane / Q000737:chemistry; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D017353:Gene Deletion; D023061:Gene Order; D005816:Genetic Complementation Test; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D009930:Organic Chemicals / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014974:Xanthomonas / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D018841:HSP90 Heat-Shock Proteins; D009930:Organic Chemicals; C066720:HtpG protein, bacteria; C046156:albicidin