Figure 6From: Structure-function relationships of wheat flavone O-methyltransferase: Homology modeling and site-directed mutagenesisHypothetical mechanism for methylation of tricetin by TaOMT2. 3'-Methylation involves an electron transfer from the γ-carboxyl group of Asp263 to the imidazole ring of His262. The electron-enriched group becomes the nucleophile that attacks the methyl group of SAM to give rise to the first methylated product, selgin.Back to article page