Premium
Structure and Biosynthesis of Myxochromides S 1–3 in Stigmatella aurantiaca : Evidence for an Iterative Bacterial Type I Polyketide Synthase and for Module Skipping in Nonribosomal Peptide Biosynthesis
Author(s) -
Wenzel Silke C.,
Kunze Brigitte,
Höfle Gerhard,
Silakowski Barbara,
Scharfe Maren,
Blöcker Helmut,
Müller Rolf
Publication year - 2005
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200400282
Subject(s) - nonribosomal peptide , polyketide , polyketide synthase , biosynthesis , biology , biochemistry , stereochemistry , chemistry , gene
The myxobacterium Stigmatella aurantiaca DW4/3–1 harbours an astonishing variety of secondary metabolic gene clusters, at least two of which were found by gene inactivation experiments to be connected to the biosynthesis of previously unknown metabolites. In this study, we elucidate the structures of myxochromides S 1–3 , novel cyclic pentapeptide natural products possessing unsaturated polyketide side chains, and identify the corresponding biosynthetic gene locus, made up of six nonribosomal peptide synthetase modules. By analyzing the deduced substrate specificities of the adenylation domains, it is shown that module 4 is most probably skipped during the biosynthetic process. The polyketide synthase MchA harbours only one module and is presumably responsible for the formation of the variable complete polyketide side chains. These data indicate that MchA is responsible for an unusual iterative polyketide chain assembly.