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Genetic interception and structural characterization of thiopeptide cyclization precursors from Bacillus cereus.

ABSTRACT: The pyridine core of the thiocillins has long been postulated to arise from a late-stage tail-to-tail condensation of two dehydroalanines. Genetic disruption of tclM, a proposed "Diels-Alderase", allowed isolation of acyclic precursors to this pyridine ring. The isolated products possess the full cohort of post-translational modifications that are normally displayed by the thiocillins, including dehydrobutyrines, thiazoles, C-terminal decarboxylation, and the two previously unconfirmed dehydroalanines. Additionally, leader peptides have undergone extensive N-terminal degradation and the remaining leader peptide residues have been N-succinylated. These results identify TclM and its homologues in other thiazolyl peptide producing strains as the enzymes responsible for the trans-annular heteroannulation at core of this class of molecules.

SUBMITTER: Bowers AA

PROVIDER: S-EPMC2932885 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature

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Genetic interception and structural characterization of thiopeptide cyclization precursors from Bacillus cereus.

Bowers Albert A AA Walsh Christopher T CT Acker Michael G MG

Journal of the American Chemical Society 20100901 35

The pyridine core of the thiocillins has long been postulated to arise from a late-stage tail-to-tail condensation of two dehydroalanines. Genetic disruption of tclM, a proposed "Diels-Alderase", allowed isolation of acyclic precursors to this pyridine ring. The isolated products possess the full cohort of post-translational modifications that are normally displayed by the thiocillins, including dehydrobutyrines, thiazoles, C-terminal decarboxylation, and the two previously unconfirmed dehydroal ...[more]

PMID: 20707374

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