Enediyne polyketide synthases stereoselectively reduce the β-ketoacyl intermediates to β-D-hydroxyacyl intermediates in enediyne core biosynthesis.

ABSTRACT: PKSE biosynthesizes an enediyne core precursor from decarboxylative condensation of eight malonyl-CoAs. The KR domain of PKSE is responsible for iterative β-ketoreduction in each round of polyketide chain elongation. KRs from selected PKSEs were investigated in vitro with β-ketoacyl-SNACs as substrate mimics. Each of the KRs reduced the β-ketoacyl-SNACs stereoselectively, all affording the corresponding β-D-hydroxyacyl-SNACs, and the catalytic efficiencies (k(cat)/K(M)) of the KRs increased significantly as the chain length of the β-ketoacyl-SNAC substrate increases.

SUBMITTER: Ge HM 

PROVIDER: S-EPMC4144755 | biostudies-literature | 2014 Aug

REPOSITORIES: biostudies-literature