Structure and function of the chalcone synthase superfamily of plant type III polyketide synthases

This review covers recent advances in structure and function studies on the chalcone synthase (CHS) superfamily of plant type III polyketide synthases (PKSs), which catalyze iterative decarboxylative condensations of malonyl unit with a CoA-linked starter molecule to produce structurally diverse, pharmaceutically important plant secondary metabolites. The functional diversity and catalytic potential of the type III PKSs are remarkable. Studies on the enzymes are now progressing rapidly; recent crystallographic and site-directed mutagenesis studies have revealed intimate structural details of the enzyme reactions, which enabled the structure-based and precursor-directed engineered biosynthesis of unnatural novel polyketides. The literature of type III PKSs of plant origin published over the last eight years will be reviewed, and is intended to compliment the coverage of the literature by Austin and Noel in Nat. Prod. Rep., 2003, 20, 79-110.