Chrysogine Biosynthesis Is Mediated by a Two-Module Nonribosomal Peptide Synthetase.

Production of chrysogine has been reported from several fungal genera including Penicillium, Aspergillus, and Fusarium. Anthranilic acid and pyruvic acid, which are expected precursors of chrysogine, enhance production of this compound. A possible route for the biosynthesis using these substrates is via a nonribosomal peptide synthetase (NRPS). Through comparative analysis of the NRPSs from genome-sequenced producers of chrysogine we identified a candidate NRPS cluster comprising five additional genes named chry2-6. Deletion of the two-module NRPS (NRPS14 = chry1) abolished chrysogine production in Fusarium graminearum, indicating that the gene cluster is responsible for chrysogine biosynthesis. Overexpression of NRPS14 enhanced chrysogine production, suggesting that the NRPS is the bottleneck in the biosynthetic pathway.