Format

Send to

Choose Destination
Chembiochem. 2018 Oct 18;19(20):2167-2172. doi: 10.1002/cbic.201800400. Epub 2018 Oct 2.

Genomics-Driven Discovery of a Symbiont-Specific Cyclopeptide from Bacteria Residing in the Rice Seedling Blight Fungus.

Author information

1
Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstrasse 11a, 07745, Jena, Germany.
2
BioPilotPlant, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Beutenbergstrasse 11a, 07745, Jena, Germany.
3
Friedrich Schiller University Jena, 07743, Jena, Germany.

Abstract

The rice seedling blight fungus Rhizopus microsporus harbors endosymbiotic bacteria (Burkholderia rhizoxinica) that produce the virulence factor rhizoxin and control host development. Genome mining indicated a massive inventory of cryptic nonribosomal peptide synthetase (NRPS) genes, which have not yet been linked to any natural products. The discovery and full characterization of a novel cyclopeptide from endofungal bacteria is reported. In silico analysis of an orphan, symbiont-specific NRPS predicted the structure of a nonribosomal peptide, which was targeted by LC-MS/MS profiling of wild-type and engineered null mutants. NMR spectroscopy and chemical derivatization elucidated the structure of the bacterial cyclopeptide. Phylogenetic analyses revealed the relationship of starter C domains for rare N-acetyl-capped peptides. Heptarhizin is produced under symbiotic conditions in geographically constrained strains from the Pacific clade; this indicates a potential ecological role of the peptide.

KEYWORDS:

cyclopeptides; enzymes; genomics; natural products; symbiotic bacteria

PMID:
30113119
DOI:
10.1002/cbic.201800400

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center