title: Diversity of type I polyketide synthase genes in the wood-decay fungus Xylaria sp. BCC 1067.
abstract: Fungal type I polyketide (PK) compounds are highly valuable for medical treatment and extremely diverse in structure, partly because of the enzymatic activities of reducing domains in polyketide synthases (PKSs). We have cloned several PKS genes from the fungus Xylaria sp. BCC 1067, which produces two polyketides: depudecin (reduced PK) and 19,20-epoxycytochalasin Q (PK-nonribosomal peptide (NRP) hybrid). Two new degenerate primer sets, KA-series and XKS, were designed to amplify reducing PKS and PKS-NRP synthetase hybrid genes, respectively. Five putative PKS genes were amplified in Xylaria using KA-series primers and two more with the XKS primers. All seven are predicted to encode proteins homologous to highly reduced (HR)-type PKSs. Previously designed primers in LC-, KS-, and MT-series identified four additional PKS gene fragments. Selected PKS fragments were used as probes to identify PKS genes from the genomic library of this fungus. Full-length sequences for five PKS genes were obtained: pks12, pks3, pksKA1, pksMT, and pksX1. They are structurally diverse with 1-9 putative introns and products ranging from 2162 to 3654 amino acids in length. The finding of 11 distinct PKS genes solely by means of PCR cloning supports that PKS genes are highly diverse in fungi. It also indicates that our KA-series primers can serve as powerful tools to reveal the genetic potential of fungi in production of multiple types of HR PKs, which the conventional compound screening could underestimate.
authors.affiliation: Combinatorial Biosynthesis Laboratory, National Center for Genetic Engineering and Biotechnology, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand. alongkorn@biotech.or.th
authors.forename: Alongkorn
authors.initials: A
authors.lastname: Amnuaykanjanasin
authors.forename: Juntira
authors.initials: J
authors.lastname: Punya
authors.forename: Porntip
authors.initials: P
authors.lastname: Paungmoung
authors.forename: Amporn
authors.initials: A
authors.lastname: Rungrod
authors.forename: Anuwat
authors.initials: A
authors.lastname: Tachaleat
authors.forename: Somchai
authors.initials: S
authors.lastname: Pongpattanakitshote
authors.forename: Supapon
authors.initials: S
authors.lastname: Cheevadhanarak
authors.forename: Morakot
authors.initials: M
authors.lastname: Tanticharoen
mesh_terms: D001203:Ascomycota / Q000201:enzymology / Q000235:genetics*; D017931:DNA Primers; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D014644:Genetic Variation; D007438:Introns; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D048630:Polyketide Synthases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D004271:DNA, Fungal; D005656:Fungal Proteins; D048630:Polyketide Synthases