label: (S)-tetrahydroprotoberberine N-methyltransferase activity
label_lc: (s)-tetrahydroprotoberberine n-methyltransferase activity
description: "Catalysis of the reaction: S-adenosyl-L-methionine + (S)-7,8,13,14-tetrahydroprotoberberine = S-adenosyl-L-homocysteine + cis-N-methyl-(S)-7,8,13,14-tetrahydroprotoberberine."