Fig. 2 in A single residue determines substrate preference in benzylisoquinoline alkaloid N-methyltransferases

Fig. 2. Analysis of key active site residues in BIA N-methyltransferases. (A) Primary sequence alignment of functionally validated BIA NMTs showing that residue 204 is conserved within BIA NMT subtypes (i.e. E in CNMTs and TNMTs, G in RNMTs, A in PavNMTs) whereas residues previously suggested to form a catalytic dyad (E207 and H208) are universally conserved. (B, C) Docking of RNMT substrate (S)-reticuline (cyan) into the active site of (B) CjCNMT (PDB 6GKV) and (C) PsRNMT (homology model) reveals a steric clash between the N-methyl group and residue E204 but not G204. S-Adenosylhomocysteine is shown in pink. Spheres represent Van der Waals radii and the distance between key atoms is given in angstroms.