D-Galactose-Esterification of a Fungal Polyketide Catalyzed by a Carnitine Acyltransferase Domain.

ABSTRACT: While sugar-containing natural products are commonly biosynthesized via glycosyltranferases using sugar-UDP as the electrophile, nature has evolved alternative strategies of glyco-modification to expand the diversity of natural products. Hydroxyl groups on sugars can serve as nucleophiles in the release of polyketide products from polyketide synthases. Herein, we demonstrate a highly reducing polyketide synthase (HRPKS) from the biocontrol fungus Trichoderma afroharzianum T22, which is terminated with a carnitine acyltransferase (cAT) domain, catalyzes the biosynthesis of a d-galactose esterified polyketide named as trichogalactin. Structure-guided enzymatic assays showed that the sugar nucleophile in the esterification reaction catalyzed by cAT is α-d-galactose-1-phosphate (Gal-1-P) inste

SUBMITTER: Nagasawa KK 

PROVIDER: S-EPMC12145579 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature