Solving the Puzzle of One‐Carbon Loss in Ripostatin Biosynthesis. Issue 8 (18th January 2017)

• Record Type: Journal Article
• Authors: Fu, Chengzhang; Auerbach, David; Li, Yanyan; Scheid, Ullrich; Luxenburger, Eva; Garcia, Ronald; Irschik, Herbert; Müller, Rolf
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 8(2017)
• Page Start: 2192
• Page End: 2197
• Publication Date: 2017-01-18
• Subjects: biosynthesis -- phenylpyruvate -- polyketide synthases -- pyruvate dehydrogenase complex -- ripostatin; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201609950
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Ripostatin is a promising antibiotic that inhibits RNA polymerase by binding to a novel binding site. In this study, the characterization of the biosynthetic gene cluster of ripostatin, which is a peculiar polyketide synthase (PKS) hybrid cluster encoding cis‐ and trans‐acyltransferase PKS genes, is reported. Moreover, an unprecedented mechanism for phenyl acetic acid formation and loading as a starter unit was discovered. This phenyl‐C2 unit is derived from phenylpyruvate (phenyl‐C3) and the mechanism described herein explains the mysterious loss of one carbon atom in ripostatin biosynthesis from the phenyl‐C3 precursor. Through in vitro reconstitution of the whole loading process, a pyruvate dehydrogenase like protein complex was revealed that performs thiamine pyrophosphate dependent decarboxylation of phenylpyruvate to form a phenylacetyl‐ S ‐acyl carrier protein species, which is supplied to the subsequent biosynthetic assembly line for chain extension to finally yield ripostatin. Abstract : Now you C it, now you don't : In ripostatin biosynthesis, a pyruvate dehydrogenase like protein complex utilizing phenylpyruvate was discovered. In vitro reconstitution and full biochemical characterization of the phenylpyruvate dehydrogenase complex revealed how the phenyl acetic acid is derived from phenylpyruvate. The results suggested a mechanism that explains the mysterious loss of one carbon atom from the known phenyl‐C3 precursor in ripostatin biosynthesis.