A catalytic triad - Lys-Asn-Asp - Is essential for the catalysis of the methyl transfer in plant cation-dependent O-methyltransferases

Theoretical calculations and experimental evidence suggest that a proton relay involving Lys157-Asn181-Asp228 is essential for the methyl transfer in cation-dependent O-methyltransferases (CCoAOMTs), although other scenarios cannot be ruled out.