Alignment of the predicted amino acid sequences of VvOMT1, VvOMT2, VvOMT3, and VvOMT4. I to V, amino acid domains conserved among plant OMTs. ↑, SAM-binding residues; C, catalytic residues; S, substrate-binding residues of MsIOMT (for M. sativa Isoflavone OMT) as determined by Zubieta et al. (2001). The black and gray shading represents identical and similar amino acids, respectively.