In silico identification and structure function analysis of a putative coclaurine N-methyltransferase from Aristolochia fimbriata

•Analysis of a coclaurine N-methyltransferase from the basal angiosperm A. fimbriata.•CNMTs are central enzymes in the biosynthesis of ethnopharmacological compounds.•Computational tools were used to predict a three-dimensional homology model.•Also to investigate the function of the protein and its mechanism for methylation.•CNMT activity follows an SN2-type mechanism involving residues Tyr79 and Glu96.