Reaction: ecgonine methyl ester + NADP+ = ecgonone methyl ester + NADPH + H+
Glossary: ecgonine methyl ester = 2β-carbomethoxy-3β-tropine = methyl (1R,2R,3S,5S)-3-hydroxy-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate
ecgonone methyl ester = 2β-carbomethoxy-3-tropinone = methyl (1R,2R,5S)-8-methyl-3-oxo-8-azabicyclo[3.2.1]octane-2-carboxylate
Other name(s): MecgoR (gene name)
Systematic name: ecgonine methyl ester:NADP+ oxidoreductase
Comments: The enzyme from the plant Erythroxylum coca catalyses the penultimate step in the biosynthesis of cocaine. In vivo the reaction proceeds in the opposite direction. With NADH instead of NADPH the reaction rate is reduced to 14%. The enzyme also reduces tropinone, nortropinone and 6-hydroxytropinone but with lower reaction rates.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
1. Jirschitzka, J., Schmidt, G.W., Reichelt, M., Schneider, B., Gershenzon, J. and D'Auria, J.C. Plant tropane alkaloid biosynthesis evolved independently in the Solanaceae and Erythroxylaceae. Proc. Natl. Acad. Sci. USA 109 (2012) 10304-10309. [PMID: 22665766]