Reaction: 2 S-adenosyl-L-methionine + 3-(aminomethyl)indole = 2 S-adenosyl-L-homocysteine + gramine (overall reaction)
(1a) S-adenosyl-L-methionine + 3-(aminomethyl)indole = S-adenosyl-L-homocysteine + (1H-indol-3-yl)-N-methylmethanamine
(1b) S-adenosyl-L-methionine + (1H-indol-3-yl)-N-methylmethanamine = S-adenosyl-L-homocysteine + gramine
For diagram of reaction click here.
Glossary: 3-(aminomethyl)indole = (1H-indol-3-yl)methanamine
gramine = (1H-indol-3-ylmethyl)dimethylamine = (1H-indol-3-yl)-N,N-dimethylmethanamine
Other name(s): NMT (gene name)
Systematic name: S-adenosyl-L-methionine:3-(aminomethyl)indole N-methyltransferase (gramine-forming)
Comments: The enzyme, characterized from Hordeum vulgare (barley), catalyses two successive N-methylation reactions during the biosynthesis of gramine, a toxic indole alkaloid.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Leland, T.J. and Hanson, A.D. Induction of a specific N-methyltransferase enzyme by long-term heat stress during barley leaf growth. Plant Physiol. 79 (1985) 451-457. [PMID: 16664431]
2. Larsson, K.A., Zetterlund, I., Delp, G. and Jonsson, L.M. N-Methyltransferase involved in gramine biosynthesis in barley: cloning and characterization. Phytochemistry 67 (2006) 2002-2008. [PMID: 16930646]