STRUCTURE DETERMINATION, BIOCHEMICAL CHARACTERIZATION, AND PROTEIN ENGINEERING OF THE ACYL CARRIER PROTEIN DOMAIN FROM 6-DEOXYERYTHRONOLIDE B SYNTHASE

Abstract

Polyketides are an important class of natural products. 6-Deoxyerythronolide B Synthase (DEBS) is a type 1 polyketide synthase that produces the Polyketide antibiotic drug erythromycin. DEBS is a large multi-domain enzyme complex containing multiple enzymatic domains, including acyl carrier protein (ACP). ACPs are involved in chain transfer and chain elongation during polyketide biosynthesis. Structural characterization of all seven ACPs could lead to a better understanding of the domain-domain interaction and the mechanism of action of the DEBS complex. Some polyketide synthases contains tandem ACP domains and the number of constituting ACPs may dictate the rate of product formation. We have engineered a similar tandem ACP architecture for the DEBS complex and have improved of the biosynthetic rate. Our study will provide structural and mechanistic information on single and tandem ACPs within the context of a modular type 1 polyketide synthase protein.