O-methyltransferase; part of the gene cluster that mediates the biosynthesis of azaterrilone A and other azaphilones, a class of fungal metabolites characterized by a highly oxygenated pyrano-quinone bicyclic core and exhibiting a broad range of bioactivities (PubMed:35398258). The first step of the pathway begins with the non-reducing polyketide synthase tazA that assembles one acetyl-CoA starter unit, five malonyl-CoA units, and catalyzes a series of Claisen condensations, methylation, PT-mediated cyclization, and finally releases the first hexaketide precursor through the R-domain. The tazA product then undergoes reduction on its terminal ketone and the following pyran-ring formation by yet undetermined enzyme(s). Dehydration and enoyl reduction, possibly involving the trans-enoyl reductase tazE leads to the next intermediate. TazD is predicted as an acetyltransferase and might catalyze the acetylation steps leading to the synthesis of azaterrilone A. Azaterrilone A is not the final product of the taz pathway and both the highly reducing polyketide synthase tazB and the dual enzyme tazHJ catalyze late steps of the pathway, leading to the production of the 2 final stereoisomers that contain additional polyketide modification whose structures have still to be determined (Probable). Secondary metabolite biosynthesis. Expression is positively regulated by the azaterrilone A cluster-specific transcription factor tazR. Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-independent O-methyltransferase family.