1. Solving the Puzzle of One-Carbon Loss in Ripostatin Biosynthesis.
- Author
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Fu, Chengzhang, Auerbach, David, Li, Yanyan, Scheid, Ullrich, Luxenburger, Eva, Garcia, Ronald, Irschik, Herbert, and Müller, Rolf
- Subjects
ANTIBIOTICS ,RNA polymerases ,BIOSYNTHESIS ,BINDING sites ,POLYKETIDE synthases ,CHEMICAL precursors - 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 FROM AUTHOR]
- Published
- 2017
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