Monday, July 27, 2009 - 3:55 PM
S51

The curious case of dinoflagellate polyketide biosynthesis

Jeffrey L. C. Wright, Center for Marine Science, UNC Wilmington, 5600 Marvin Moss Lane, Wilmington, NC 28409

Polyketide-derived secondary metabolites are among the most common secondary metabolites produced by bacteria and fungi, and are assembled by a polyketide synthase (PKS) using an established process of linking intact acetate units, forming a nascent polyketide chain which may undergo additional processing to yield the final product.  Polyketides produced by marine dinoflagellates are distinct in that their chemistry is unique, frequently containing several ether rings either in isolation or trans-fused to form the characteristic ladder-frame polyether ring systems. In addition, a typical dinoflagellate polyketide is not composed entirely of intact acetate units but often contains deleted units where the carboxyl carbon has been excised and the methyl carbon retained in the chain.   Furthermore within dinoflagellate metabolites, the pendant methyl groups, typically derived from S-adenosyl methionine (SAM) in microbial polyketides, are more commonly derived from the methyl group of acetate. Dinoflagellate genetics is complex and challenging and this has hindered a better understanding of these and other related biosynthetic processes at the molecular level.  However, progress can be made through chemical and biochemical studies which provide another window through which to view dinoflagellate polyketide synthesis and the subsequent assembly steps to create these interesting molecules.  A short overview of dinoflagellate polyketide synthesis will be presented, together with some of our most recent results in this area.