Tricetin 3',4',5' O trimethyltransferase

Tricetin 3',4',5'-O-trimethyltransferase (EC 2.1.1.169, FOMT, TaOMT1, TaCOMT1, TaOMT2) is an enzyme with systematic name S-adenosyl-L-methionine:tricetin 3',4',5'-O-trimethyltransferase. This enzyme catalyses the following chemical reaction

3 S-adenosyl-L-methionine + tricetin ⇌ 3 S-adenosyl-L-homocysteine + 3',4',5'-O-trimethyltricetin (overall reaction)(1a) S-adenosyl-L-methionine + tricetin ⇌ S-adenosyl-L-homocysteine + 3'-O-methyltricetin(1b) S-adenosyl-L-methionine + 3'-O-methyltricetin ⇌ S-adenosyl-L-homocysteine + 3',5'-O-dimethyltricetin(1c) S-adenosyl-L-methionine + 3',5'-O-dimethyltricetin ⇌ S-adenosyl-L-homocysteine + 3',4',5'-O-trimethyltricetin

The enzyme from Triticum aestivum catalyses the sequential O-methylation of tricetin via 3'-O-methyltricetin, 3',5'-O-methyltricetin to 3',4',5'-O-trimethyltricetin.