label: N(alpha)-methyl-L-histidine + S-adenosyl-L-homocysteine + H(+) => L-histidine + S-adenosyl-L-methionine
label_lc: n(alpha)-methyl-l-histidine + s-adenosyl-l-homocysteine + h(+) => l-histidine + s-adenosyl-l-methionine