In work on polyketide biosynthesis, a combination of synthetic, enzymological, and molecular genetic approaches is being used to clarify the intricate sequence of events that is required to convert the simple building blocks acetate and propionate to complex macrolides such as the broad spectrum antibiotic erythromycin A and other antibiotics. In collaboration with Prof. Chaitan Khosla and his group at Stanford, the mechanism of polyketide chain elongation has been studied directly at the enzyme level using cloned 6-deoxyerythonolide B synthase and various truncated mutants to establish the mechanistic and structural basis for the programming of complex polyketide biosynthesis.