Requires Mg2+, Mn2+ or Co2+. The 3-hydroxy group of a 2-O-methyl-6-deoxy-D-allose residue in the macrolide antibiotic macrosin acts as methyl acceptor. Isolated from Streptomyces fradiae. Tylosin is a macrolide antibiotic. Not identical with EC 2.1.1.102, demethylmacrocin O-methyltransferase.