Discovery of a New Bacterial Polyketide Biosynthetic Pathway

Biochemically and phylogenetically unrelated to the well-characterized microbial polyketide synthases (PKSs), which are responsible for the biosynthesis of many clinically important natural products, is a new family of PKSs recently discovered in bacteria. These new enzymes, termed type III PKSs, may be the predecessors to the plant PKSs, and their study promises insights into a new condensing reaction towards small aromatic metabolites in bacteria (see scheme).