N(tau)-methylhistamine + S-adenosyl-L-homocysteine + H(+) => histamine + S-adenosyl-L-methionine
n(tau)-methylhistamine + s-adenosyl-l-homocysteine + h(+) => histamine + s-adenosyl-l-methionine
N(tau)-methylhistamine + S-adenosyl-L-homocysteine + H(+) => histamine + S-adenosyl-L-methionine
n(tau)-methylhistamine + s-adenosyl-l-homocysteine + h(+) => histamine + s-adenosyl-l-methionine