Phenalenone Polyketide Cyclization Catalyzed by Fungal Polyketide Synthase and Flavin-Dependent Monooxygenase.

ABSTRACT: Phenalenones are polyketide natural products that display diverse structures and biological activities. The core of phenalenones is a peri-fused tricyclic ring system cyclized from a linear polyketide precursor via an unresolved mechanism. Toward understanding the unusual cyclization steps, the phn biosynthetic gene cluster responsible for herqueinone biosynthesis was identified from the genome of Penicillium herquei. A nonreducing polyketide synthase (NR-PKS) PhnA was shown to synthesize the heptaketide backbone and cyclize it into the angular, hemiketal-containing naphtho-γ-pyrone prephenalenone. The product template (PT) domain of PhnA catalyzes only the C4-C9 aldol condensation, which is unprecedented among known PT domains. The transformation of prephenalenone to phenalenone requires

SUBMITTER: Gao SS 

PROVIDER: S-EPMC4988900 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature