Premium
Genomics‐Driven Discovery of a Symbiont‐Specific Cyclopeptide from Bacteria Residing in the Rice Seedling Blight Fungus
Author(s) -
Niehs Sarah P.,
Dose Benjamin,
Scherlach Kirstin,
Roth Martin,
Hertweck Christian
Publication year - 2018
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.201800400
Subject(s) - nonribosomal peptide , biology , in silico , bacteria , fungus , gene , burkholderia , peptide , genome , magnaporthe grisea , microbiology and biotechnology , genetics , biochemistry , botany , oryza sativa , biosynthesis
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.