Solanapyrone synthase, a possible Diels-Alderase and iterative type I polyketide synthase encoded in a biosynthetic gene cluster from Alternaria solani

Chembiochem. 2010 Jun 14;11(9):1245-52. doi: 10.1002/cbic.201000173.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternaria / enzymology*
  • Biocatalysis
  • Circular Dichroism
  • Cyclization
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Intramolecular Oxidoreductases / genetics
  • Intramolecular Oxidoreductases / metabolism*
  • Multigene Family
  • Naphthalenes / chemistry
  • Naphthalenes / metabolism
  • Oxidation-Reduction
  • Polyketide Synthases / genetics
  • Polyketide Synthases / metabolism*
  • Pyrones / chemistry
  • Pyrones / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Stereoisomerism

Substances

  • Fungal Proteins
  • Naphthalenes
  • Pyrones
  • Recombinant Proteins
  • Polyketide Synthases
  • solanapyrone A
  • Intramolecular Oxidoreductases
  • solanapyrone synthase