On-PKS Baeyer-Villiger-Type O-Atom Insertion Catalyzed by Luciferase-Like Monooxygenase OvmO during Olimycin Biosynthesis.

A silent ansamycin biosynthetic gene cluster (ovm) was activated in Streptomyces olivaceus SCSIO T05 following mutagenesis and media optimization. A new shunt product, olimycin C (1a) was produced by the ovmO-inactivated mutant strain, along with a minor product, olimycin D (1b). The production of these linear olimycin counterparts suggest that luciferase-like monooxygenase (LLM) OvmO catalyzes an on-PKS Baeyer-Villiger-type oxidation during assembly of the olimycin A (2) linear polyketide backbone.