In this study, the researchers found that flavin binding enzyme FlsO1 from Micromonospora rosaria SCSIO N160could catalyze multistep of oxidations (including hydroxylation, epoxidation and Baeyer-Villiger oxidation).
FlsO1 converted prejadomycin to multiple products including dehydrorabelomycin (compensating the physiological role of FlsO2), and compounds fluoxanthone A-B and fluoxanol. Using nenestatin C as the mimic substrate, FlsO1 was physiologically characterized as a benzofluorene C-5 hydrxoylase in the biosynthesis of atypical angucyclines, and a broad substrate binding cavity in the resolved crystal structure of FlsO1 explained the functional promiscuity of FlsO1.
This study provides biochemical evidence to support the physiological function of FlsO1 and reveals its underlying mechanism and structure base for the multistep of oxidations.
Figure 1. The physiological and unexpected functions of the multi-functional monooxygenase FlsO1.(Image by SCSIO)
Figure 2. The enzymatic mechanism of FlsO1-catalyzed xanthone formation. (Image by SCSIO)