Identification and Functional Characterization of Fungal Chalcone Synthase and Chalcone Isomerase

By mining fungal genomic information, a non-canonical iterative type I PKS fused with an N-terminal adenylation-thiolation didomain, which catalyzes the formation of naringenin chalcone, was found. Structural prediction and molecular docking analysis indicated that a C-terminal thioesterase domain was involved in the Claisen-type cyclization. An enzyme responsible for formation of (2S)-flavanone in the biosynthesis of fungal flavonoids was also identified. Collectively, these findings demonstrate unprecedented fungal biosynthetic machinery leading to plant-like metabolites. fungal CHS A T I KS S o AT DH KR ACP TE R funaal QHI HO OH O OH O chalcones (2S)-flavanones