:Tricin synthase

{{Infobox enzyme

| Name = Tricin synthase

| EC_number = 2.1.1.175

| CAS_number =

| GO_code =

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Tricin synthase ({{EC number|2.1.1.175}}, ROMT-17, ROMT-15, HvOMT1, ZmOMT1) is an enzyme with systematic name S-adenosyl-L-methionine:tricetin 3',5'-O-dimethyltransferase.{{cite journal | title = Cation dependent O-methyltransferases from rice |author1 = Lee, Y.J. |author2 =Kim, B.G. |author3 =Chong, Y. |author4 =Lim, Y. |author5 =Ahn, J.H. |journal = Planta |date = 2008 |volume = 227 |pages = 641–647 |pmid = 17943312 |doi=10.1007/s00425-007-0646-4}}{{cite journal | title = Characterization of two O-methyltransferase-like genes in barley and maize |vauthors = Zhou JM, Fukushi Y, Wollenweber E, Ibrahim RK |journal = Pharm. Biol. |date = 2008 |volume = 46 |pages = 26–34 |doi=10.1080/13880200701729745|doi-access = free }} This enzyme catalyses the following chemical reaction

: 2 S-adenosyl-L-methionine + tricetin $\backslash rightleftharpoons$ 2 S-adenosyl-L-homocysteine + 3',5'-O-dimethyltricetin (overall reaction)

:(1a) S-adenosyl-L-methionine + tricetin $\backslash rightleftharpoons$ S-adenosyl-L-homocysteine + 3'-O-methyltricetin

:(1b) S-adenosyl-L-methionine + 3'-O-methyltricetin $\backslash rightleftharpoons$ S-adenosyl-L-homocysteine + 3',5'-O-dimethyltricetin

The enzymes from Oryza sativa (ROMT-15 and ROMT-17) catalyses the stepwise methylation of tricetin to its 3'-mono- and 3',5'-dimethyl ethers.