4-methylamino-4-dedimethylamino-anhydrotetracycline + S-adenosyl-L-methionine = anhydrotetracycline + S-adenosyl-L-homocysteine + H(+)
4-methylamino-4-dedimethylamino-anhydrotetracycline + s-adenosyl-l-methionine = anhydrotetracycline + s-adenosyl-l-homocysteine + h(+)
4-methylamino-4-dedimethylamino-anhydrotetracycline + S-adenosyl-L-methionine = anhydrotetracycline + S-adenosyl-L-homocysteine + H(+)
4-methylamino-4-dedimethylamino-anhydrotetracycline + s-adenosyl-l-methionine = anhydrotetracycline + s-adenosyl-l-homocysteine + h(+)