title: Exploring the diversity of marine-derived fungal polyketide synthases.
abstract: Using an approach based on polymerase chain reaction (PCR), we examined the diversity of polyketide synthase (PKS) genes present in 160 marine fungal isolates, representing 142 species. We obtained ketosynthase (KS) domain PCR products from 99 fungal isolates, representing Dothideomycetes, Sordariomycetes, Eurotiomycetes, and incertae sedis. Sequence similarity searches and phylogenetic analysis of 29 marine partial-KS-encoding sequences revealed domains predicted to encode reducing, nonreducing, and 6-methylsalicylic acid PKSs. Bioinformatic analysis of an alignment of the KS sequences from marine-derived fungi revealed no unique motifs in this region. However, several specificity-determining positions were apparent between fungal 6-methylsalicylic acid PKSs as compared with either reducing or nonreducing PKSs. Evaluation of these positions in the context of a modelled three-dimensional protein structure highlighted their potential use as PKS classification markers. Evaluating primer-binding sites was necessary to obtain KS domain fragments from putative PKSs while maintaining a level of sequence information adequate to properly classify and characterize them.
authors.affiliation: Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin Moss Lane, Wilmington, NC 28409, USA.
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Mayer
authors.forename: Jermaine
authors.initials: J
authors.lastname: Ford
authors.forename: Gordon R
authors.initials: GR
authors.lastname: Macpherson
authors.forename: David
authors.initials: D
authors.lastname: Padgett
authors.forename: Brigitte
authors.initials: B
authors.lastname: Volkmann-Kohlmeyer
authors.forename: Jan
authors.initials: J
authors.lastname: Kohlmeyer
authors.forename: Colleen
authors.initials: C
authors.lastname: Murphy
authors.forename: Susan E
authors.initials: SE
authors.lastname: Douglas
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Wright
authors.forename: Jeffrey L C
authors.initials: JL
authors.lastname: Wright
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D017124:Conserved Sequence; D005658:Fungi / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D048630:Polyketide Synthases / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction; D014871:Water Microbiology
chemical_list: D048630:Polyketide Synthases