title: Genetic locus encoding functions involved in biosynthesis and outer membrane localization of xanthomonadin in Xanthomonas oryzae pv. oryzae.
abstract: Xanthomonadins are membrane-bound, brominated, aryl-polyene pigments specific to the genus Xanthomonas. We have characterized a genetic locus (pig) from Xanthomonas oryzae pv. oryzae which contains four open reading frames (ORFs) that are essential for xanthomonadin production. Three of these ORFs are homologous to acyl carrier proteins, dehydratases, and acyl transferases, suggesting a type II polyketide synthase pathway for xanthomonadin biosynthesis. The fourth ORF has no homologue in the database. For the first time, we report that a putative cytoplasmic membrane protein encoded in the pig locus is required for outer membrane localization of xanthomonadin in X. oryzae pv. oryzae. We also report the identification of a novel 145-bp palindromic Xanthomonas repetitive intergenic consensus element that is present in two places in the pig locus. We estimate that more than 100 copies of this element might be present in the genome of X. oryzae pv. oryzae and other xanthomonads.
authors.affiliation: Centre for Cellular and Molecular Biology, Hyderabad 500 007, Andhra Pradesh, India.
authors.forename: Ajay Kumar
authors.initials: AK
authors.lastname: Goel
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Rajagopal
authors.forename: Narayana
authors.initials: N
authors.lastname: Nagesh
authors.forename: Ramesh V
authors.initials: RV
authors.lastname: Sonti
mesh_terms: D000595:Amino Acid Sequence; D000840:Anisoles / Q000378:metabolism*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D021901:DNA, Intergenic; D004952:Esters / Q000378:metabolism*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D005810:Multigene Family; D009154:Mutation; D016366:Open Reading Frames; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D014974:Xanthomonas / Q000235:genetics* / Q000378:metabolism
chemical_list: D000840:Anisoles; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D021901:DNA, Intergenic; D004952:Esters; D009097:Multienzyme Complexes; C108932:xanthomonadin I