Formation of the Aureothin Tetrahydrofuran Ring by a Bifunctional Cytochrome P450 Monooxygenase

The polyketide antibiotic aureothin, produced by Streptomyces thioluteus, is equipped with a rare exomethylene-tetrahydrofuran moiety. Cloning, heterologous expression, and inactivation experiments reveal that AurH, a bifunctional cytochrome P450 monooxygenase, is required and sufficient for the stereoselective synthesis of the furan ring, involving the subsequent formation of two new C−O bonds.