Multiple sequence alignment among NnOMT candidates and T. flavum 6OMT (Tf6OMT). Residues shared by Tf6OMT and sacred lotus OMTs are shaded in gray, and fully conserved residues are shaded in black. Asterisks indicate catalytic (His256, Asp257, and Glu315) and other key residues implicated in BIA (Gly165, Asp169, Cys253, and Asp306) and SAM (Thr170, Gly195, Asp218, Asp238, and Lys252) binding, as reported for Tf6OMT. Conserved motives I–IV are underlined.