2.1.1.304 S-adenosyl-L-methionine + L-tyrosine the enzyme is involved in biosynthesis of saframycin A, a potent antitumor antibiotic that belongs to the tetrahydroisoquinoline family 2.1.1.304 S-adenosyl-L-methionine + L-tyrosine the enzyme is highly selective with regard to their natural substrate. The enzyme is involved in the biosynthesis of 3'-methyltyrosine, which is the precursor of the tetrahydroisoquinoline moiety in Saframycin (antibiotic) 2.1.1.304 S-adenosyl-L-methionine + L-tyrosine the enzyme is involved in the biosynthesis of 3'-methyltyrosine, which is the precursor of the tetrahydroisoquinoline moiety in Safracin (antibiotic)