Crystal Structures of SgcE6 and SgcC, the Two-Component Monooxygenase That Catalyzes Hydroxylation of a Carrier Protein-Tethered Substrate during the Biosynthesis of the Enediyne Antitumor Antibiotic C-1027 in Streptomyces globisporus.

ABSTRACT: C-1027 is a chromoprotein enediyne antitumor antibiotic produced by Streptomyces globisporus. In the last step of biosynthesis of the (S)-3-chloro-5-hydroxy-β-tyrosine moiety of the C-1027 enediyne chromophore, SgcE6 and SgcC compose a two-component monooxygenase that hydroxylates the C-5 position of (S)-3-chloro-β-tyrosine. This two-component monooxygenase is remarkable for two reasons. (i) SgcE6 specifically reacts with FAD and NADH, and (ii) SgcC is active with only the peptidyl carrier protein (PCP)-tethered substrate. To address the molecular details of substrate specificity, we determined the crystal structures of SgcE6 and SgcC at 1.66 and 2.63 Å resolution, respectively. SgcE6 shares a similar β-barrel fold with the class I HpaC-like flavin reductases. A flexible loop near the acti

SUBMITTER: Chang CY 

PROVIDER: S-EPMC5024704 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature