(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase;
norreticuline N-methyltransferase

Transferases;
Transferring one-carbon groups;
Methyltransferases

S-adenosyl-L-methionine:(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase

S-adenosyl-L-methionine + (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline = S-adenosyl-L-homocysteine + N-methyl-(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline [RN:R04713]

R04713;
(other) R04692 R05211 R05216 R08794

S-adenosyl-L-methionine [CPD:C00019];
(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline [CPD:C05201]

Broad substrate specificity for (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinolines; including coclaurine, norcoclaurine, isococlaurine, norarmepavine, norreticuline and tetrahydropapaverine. Both R- and S-enantiomers are methylated. The enzyme participates in the pathway leading to benzylisoquinoline alkaloid synthesis in plants. The physiological substrate is likely to be coclaurine. The enzyme was earlier termed norreticuline N-methyltransferase. However, norreticuline has not been found to occur in nature and that name does not reflect the broad specificity of the enzyme for (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinolines.

1

Frenzel, T., Zenk, M.H.

Purification and characterization of three isoforms of S-adenosyl-L-methionine: (R,S)-tetrahydrobenzyl-isoquinoline N-methyltransferase from Berberis koetineana cell cultures.

Phytochemistry 29 (1990) 3491-3497.