Reaction: (1) 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
Other name(s): FOMT; TaOMT1; TaCOMT1; TaOMT2
Systematic name: S-adenosyl-L-methionine:tricetin 3',4',5'-O-trimethyltransferase
Comments: 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 [2].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Kornblatt, J.A., Zhou, J.M. and Ibrahim, R.K. Structure-activity relationships of wheat flavone O-methyltransferase: a homodimer of convenience. FEBS J. 275 (2008) 2255-2266. [PMID: 18397325]
2. Zhou, J.M., Gold, N.D., Martin, V.J., Wollenweber, E. and Ibrahim, R.K. Sequential O-methylation of tricetin by a single gene product in wheat. Biochim. Biophys. Acta 1760 (2006) 1115-1124. [PMID: 16730127]
3. Zhou, J.M., Seo, Y.W. and Ibrahim, R.K. Biochemical characterization of a putative wheat caffeic acid O-methyltransferase. Plant Physiol. Biochem. 47 (2009) 322-326. [PMID: 19211254]