Solanapyrone Synthase, a Possible Diels–Alderase and Iterative Type I Polyketide Synthase Encoded in a Biosynthetic Gene Cluster from Alternaria solani

✍ Scribed by Ken Kasahara ; Takanori Miyamoto; Takashi Fujimoto; Hiroki Oguri; Tetsuo Tokiwano ; Hideaki Oikawa; Yutaka Ebizuka; Isao Fujii

• Book ID: 101817573
• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 255 KB
• Volume: 11
• Category: Article
• ISSN: 1439-4227
• DOI: 10.1002/cbic.201000173

✦ Synopsis

Abstract

The solanapyrone biosynthetic gene cluster was cloned from Alternaria solani__. It consists of six genes—sol1–6—coding for a polyketide synthase, an__ O__‐methyltransferase, a dehydrogenase, a transcription factor, a flavin‐dependent oxidase, and cytochrome P450. The prosolanapyrone synthase (PSS) encoded by__ sol1 was expressed in Aspergillus oryzae and its product was identified as desmethylprosolanapyrone I (8). Although PSS is closely related to the PKSs/Diels–Alderases LovB and MlcA of lovastatin and compactin biosynthesis, it did not catalyze cycloaddition. Sol5, encoding a flavin‐dependent oxidase (solanapyrone synthase, SPS), was expressed in Pichia pastoris and purified. The purified recombinant SPS showed activity for the formation of (−)‐solanapyrone A (1) from achiral prosolanapyrone II (2), establishing that this single enzyme catalyzes both the oxidation and the subsequent cycloaddition reaction, possibly as a Diels–Alder enzyme.