Two genes, <italic>rif15</italic> and <italic>rif16</italic>, of the rifamycin biosynthetic gene cluster in <italic>Amycolatopsis mediterranei</italic> likely encode a transketolase and a P450 monooxygenase, respectively, both essential for the conversion of rifamycin SV into B

Amycolatopsis mediterranei produces an important antibiotic rifamycin, the biosynthesis of which involves many unusual modifications. Previous work suggested a putative P450 enzyme encoded by rif16 within the rifamycin biosynthetic gene cluster (rif) was required for the conversion of the intermediate rifamycin SV into the end product rifamycin B. In this study, we genetically proved that a putative transketolase encoded by rif15 is another...