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In Vitro Biosynthesis of the Core Scaffold of the Thiopeptide Thiomuracin.

ABSTRACT: Thiopeptides are potent antibiotics that inhibit protein synthesis. They are made by a remarkable post-translational modification process that transforms a linear peptide into a polycyclic structure. We present here the in vitro biosynthesis of the core scaffold of thiomuracin catalyzed by six proteins. We show that cyclodehydration precedes dehydration, and that dehydration is catalyzed by two proteins in a tRNA(Glu)-dependent manner. The enzyme that generates the pyridine core from two dehydroalanines ejects the leader peptide as a C-terminal carboxamide. Mutagenesis studies of the enzyme TbtD identified important residues for a formal [4+2] cycloaddition process. The core structure of thiomuracin exhibits similar antimicrobial activity to other known congeners, illustrating that in vitro biosynthesis is a viable route to potent antibiotics that can be explored for the rapid and renewable generation of analogues.

SUBMITTER: Hudson GA

PROVIDER: S-EPMC4819586 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature

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In Vitro Biosynthesis of the Core Scaffold of the Thiopeptide Thiomuracin.

Hudson Graham A GA Zhang Zhengan Z Tietz Jonathan I JI Mitchell Douglas A DA van der Donk Wilfred A WA

Journal of the American Chemical Society 20151221 51

Thiopeptides are potent antibiotics that inhibit protein synthesis. They are made by a remarkable post-translational modification process that transforms a linear peptide into a polycyclic structure. We present here the in vitro biosynthesis of the core scaffold of thiomuracin catalyzed by six proteins. We show that cyclodehydration precedes dehydration, and that dehydration is catalyzed by two proteins in a tRNA(Glu)-dependent manner. The enzyme that generates the pyridine core from two dehydro ...[more]

PMID: 26675417

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