Cytochrome P450 monooxygenase; part of the gene cluster that mediates the biosynthesis of radicicol, a resorcylic acid lactone (RAL) that irreversibly inhibits the HSP90 molecular chaperone, an important target for cancer chemotherapy (PubMed:19101477). The cluster encodes only two apparent post-PKS enzymes, a cytochrome P450 monooxygenase (radP) and a non-heme halogenase (radH) that introduce the epoxide and the chlorine, respectively (PubMed:19101477). If this cluster includes all the genes required for radicicol biosynthesis, the remaining structural features of radicicol are presumably generated by the PKSs rads1 and rads2 (PubMed:19101477). The C-2' ketone could arise if the R-PKS rads1 and NR-PKS rads2 each carry out four iterations, in contrast to the five iteration-three iteration split for the hypothemycin PKSs (PubMed:19101477). The origin of the cis 5',6' double bond is not known (By similarity). The radicicol R-PKS rads1 ER domain may catalyze either double bond isomerization or reduction in the third iteration (By similarity). Secondary metabolite biosynthesis. Abolishes the production of radicicol and accumulates 14(15)-deepoxy-12(13)-dihydro-radicicol, also known as pochonin D (PubMed:19101477). Radicicol is an important pharmacophore as an inhibitor of heat shock protein 90 (Hsp90), an ATP-dependent chaperone involved in the post-translational maturation and stabilization of over one hundred proteins, and which activity has been implicated in diverse pathologies ranging from oncology to neurodegenerative and infectious diseases (PubMed:19101477). Belongs to the cytochrome P450 family.