label: 4-methylamino-4-dedimethylamino-anhydrotetracycline + S-adenosyl-L-methionine <=> anhydrotetracycline + S-adenosyl-L-homocysteine + H(+)
label_lc: 4-methylamino-4-dedimethylamino-anhydrotetracycline + s-adenosyl-l-methionine <=> anhydrotetracycline + s-adenosyl-l-homocysteine + h(+)