Heme-containing peroxygenase that mediates the hydroxylation of 3-methyl-L-tyrosine (3-Me-Tyr) into 3-hydroxy-5-methyl-L-tyrosine (3-OH-5-Me-Tyr) in biosynthesis of saframycin A, a potent antitumor antibiotic that belongs to the tetrahydroisoquinoline family. Involved in biosynthesis of 3-hydroxy-5-methyl-O-methyltyrosine (3-OH-5-Me-OMe-Tyr), a core structure of saframycin A. 3-methyl-L-tyrosine + H2O2 = 5-hydroxy-3-methyl-L-tyrosine + H2O Binds 1 heme group per subunit. kcat is 17.8 min(-1) with 3-methyl-L-tyrosine as substrate. kcat is 12.3 min(-1) with L-tyrosine as substrate. Optimum pH is 9.0. Antibiotic biosynthesis.