Carbohydrates are key structural components of numerous secondary metabolites and often play critical roles in determining the biological activity of the glycosylated natural products. In a number of instances, their biosynthesis requires radical mediated chemical transformations, some of which are catalyzed by radical SAM enzymes. For example, AprD4 catalyzes the C3 deoxygenation of paromamine, a key step in the biosynthesis of serval aminoglycosides. GenK is a cobalamin-dependent radical SAM enzyme that catalyzes the methylation of an unactivated sp3 carbon of GenX2 to produce the intermediate G418 during the biosynthesis of gentamicin. OxsB is another cobalamin-dependent radical SAM enzyme responsible for the ring contraction of 2'-deoxyadenosine 5'-monophosphate to yield the four-membered heterocycle in oxetanocin. SpeY has been proposed to catalyze dioxane ring formation in spectinomycin. Two radical SAM enzymes are also required for the assembly of albomycins. These enzymes are representative radical SAM enzymes that are involved in carbohydrate biosynthesis. The biosynthetic roles of selected enzymes in this group, their mechanisms of catalysis, and the insights they can offer for furthering our understanding of radical SAM enzymology will be discussed in this presentation.

Radical SAM enzymes in the biosynthesis of sugar-containing secondary metabolites

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.