3-methylquercetin 7-O-methyltransferase
In enzymology, a 3-methylquercetin 7-O-methyltransferase (EC 2.1.1.82) is an enzyme that catalyzes the chemical reaction
- S-adenosyl-L-methionine + 5,7,3',4'-tetrahydroxy-3-methoxyflavone S-adenosyl-L-homocysteine + 5,3',4'-trihydroxy-3,7-dimethoxyflavone
| 3-methylquercitin 7-O-methyltransferase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.1.1.82 | ||||||||
| CAS no. | 96477-62-2 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
Thus, the two substrates of this enzyme are S-adenosyl methionine and 5,7,3',4'-tetrahydroxy-3-methoxyflavone (isorhamnetin), whereas its two products are S-adenosylhomocysteine and 5,3',4'-trihydroxy-3,7-dimethoxyflavone (rhamnazin).
This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:5,7,3',4'-tetrahydroxy-3-methoxyflavone 7-O-methyltransferase. Other names in common use include flavonol 7-O-methyltransferase, flavonol 7-methyltransferase, 7-OMT, S-adenosyl-L-methionine:3',4',5,7-tetrahydroxy-3-methoxyflavone, 7-O-methyltransferase, and 3-methylquercitin 7-O-methyltransferase [mis-spelt].
The enzyme can be found in Chrysosplenium americanum (American Golden Saxifrage).
References
- De Luca V, Ibrahim RK (1985). "Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. I. Partial purification and some properties of S-adenosyl-L-methionine:flavonol 3-, 6-, 7-, and 4'-O-methyltransferases". Arch. Biochem. Biophys. 238 (2): 596–605. doi:10.1016/0003-9861(85)90205-X. PMID 3994393.