The last step in cocaine biosynthesis is catalyzed by a BAHD acyltransferase.

Plant physiology

PubMedID: 25406120

Schmidt GW, Jirschitzka J, Porta T, Reichelt M, Luck K, Pardo-Torre JC, Dolke F, Varesio E, Hopfgartner G, Gershenzon J, D'Auria J. The last step in cocaine biosynthesis is catalyzed by a BAHD acyltransferase. Plant Physiol. 2014;.
The esterification of methylecgonine (2-carbomethoxy-3ß-tropine) with benzoic acid is the final step in the biosynthetic pathway leading to the production of cocaine in Erythoxylum coca. Here we report the identification of a member of the BAHD family of plant acyltransferases as cocaine synthase. The enzyme is capable of producing both cocaine and cinnamoylcocaine via the activated benzoyl- or cinnamoyl-CoA thioesters, respectively. Cocaine synthase activity is highest in young developing leaves, especially in the palisade parenchyma and spongy mesophyll. These data correlate well with the tissue distribution pattern of cocaine as visualized with antibodies. MALDI mass spectral imaging revealed that cocaine and cinnamoyl cocaine are differently distributed on the upper vs. lower leaf surfaces. Our findings provide further evidence that tropane alkaloid biosynthesis in the Erythroxylaceae occurs in the above ground portions of the plant in contrast with the Solanaceae where tropane alkaloid biosynthesis occurs in the roots.