Identification of peptaibols from Trichoderma virens and cloning of a peptaibol synthetase.
The fungus Trichoderma virens is a ubiquitous soil saprophyte that has been applied as a biological control agent to protect plants from fungal pathogens. One mechanism of biocontrol is mycoparasitism, and T. virens produces antifungal compounds to assist in killing its fungal targets. Peptide synthetases produce a wide variety of peptide secondary metabolites in bacteria and fungi. Many of these are known to possess antibiotic activities. Peptaibols form a class of antibiotics known for their high alpha-aminoisobutyric acid content and their synthesis as a mixture of isoforms ranging from 7 to 20 amino acids in length. Here we report preliminary characterization of a 62.8-kb continuous open reading frame encoding a peptaibol synthetase from T. virens. The predicted protein structure consists of 18 peptide synthetase modules with additional modifying domains at the N- and C-termini. T. virens was shown to produce a mixture of peptaibols, with the largest peptides being 18 residues. Mutation of the gene eliminated production of all peptaibol isoforms. Identification of the gene responsible for peptaibol production will facilitate studies of the structure and function of peptaibol antibiotics and their contribution to biocontrol activity.
Wiest
Aric
A
Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA.
Grzegorski
Darlene
D
Xu
Bi-Wen
BW
Goulard
Christophe
C
Rebuffat
Sylvie
S
Ebbole
Daniel J
DJ
Bodo
Bernard
B
Kenerley
Charles
C
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D017931:DNA Primers; D005285:Fermentation; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D016366:Open Reading Frames; D010453:Peptide Synthases / Q000235:genetics*; D010455:Peptides; D014242:Trichoderma / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D017931:DNA Primers; D010455:Peptides; D010453:Peptide Synthases