activities of three human drug-metabolizing methyltransferase enzymes , catechol-o-methyltransferase ( comt ) ( ec 2.1.1.6 ) , thiopurine methyltransferase ( tpmt ) ( ec 2.1.1.67 ) , and thiol methyltransferase ( tmt ) ( ec 2.1.1.9 ) , are controlled by inheritance .
C0025831
methyltransferase
C0007407
catechol-o-methyltransferase