FAD-dependent monooxygenase; part of the gene cluster that mediates the biosynthesis of depudecin, a highly oxidized eleven-carbon linear polyketide that acts as a histone deacetylase (HDAC) inhibitor and makes a small contribution to pathogenesis (PubMed:19737099). The reducing polyketide synthase DEP5 is the central enzyme in depudecin biosynthesis by yielding the backbone polyketide chain (PubMed:19737099). The monooxygenases DEP2 and DEP4, as well as the uncharacterized protein DEP1, then act as tailoring enzymes to modify the intermediate polyketide chain into depudecin (PubMed:19737099). Polyketide biosynthesis. Expression is positively regulated by the depudecin biosynthesis cluster-specific transcription activator DEP6 (PubMed:19737099). Impairs the production of depudecin and accumulates an epoxide-containing metabolite of slightly higher retention factor than native depudecin (PubMed:19737099). Belongs to the FAD-binding monooxygenase family.