View source for Quercetin 3-O-methyltransferase

{{infobox enzyme
| Name       = quercetin 3-O-methyltransferase
| EC_number  = 2.1.1.76
| CAS_number = 75603-21-3
| GO_code    = 0030755
| image      =
| width      = 
| caption    =  
}}
In [[enzymology]], a '''quercetin 3-O-methyltransferase''' ({{EC number|2.1.1.76}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:S-adenosyl-L-methionine + 3,5,7,3',4'-pentahydroxyflavone <math>\rightleftharpoons</math> S-adenosyl-L-homocysteine + 3-methoxy-5,7,3',4'-tetrahydroxyflavone

Thus, the two [[substrate (biochemistry)|substrates]] of this enzyme are [[S-Adenosyl methionine|S-adenosyl methionine]] and [[3,5,7,3',4'-pentahydroxyflavone]], whereas its two [[product (chemistry)|products]] are [[S-adenosylhomocysteine]] and [[3-methoxy-5,7,3',4'-tetrahydroxyflavone]].

This enzyme belongs to the family of [[transferase]]s, specifically those transferring one-carbon group methyltransferases.  The [[List of enzymes|systematic name]] of this enzyme class is '''S-adenosyl-L-methionine:3,5,7,3',4'-pentahydroxyflavone 3-O-methyltransferase'''. Other names in common use include '''flavonol 3-O-methyltransferase''', and '''flavonoid 3-methyltransferase'''.  This enzyme participates in [[flavonoid biosynthesis]].

==References==
{{reflist|1}}
* {{cite journal | vauthors = Foucher AL, McIntosh A, Douce G, Wastling J, Tait A, Turner CM | date = 2006 | title = A proteomic analysis of arsenical drug resistance in Trypanosoma brucei | journal = Proteomics  | volume = 6 | pages = 2726&ndash;32  | pmid = 16526094 | doi = 10.1002/pmic.200500419 | issue = 9 }}
* {{cite journal | vauthors = De Luca V, Ibrahim RK | date = 1985 | title = 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 | journal = Arch. Biochem. Biophys.  | volume = 238 | pages = 596&ndash;605  | pmid = 3994393 | doi = 10.1016/0003-9861(85)90205-X | issue = 2 }}
* {{cite journal | vauthors = De Luca V, Ibrahim RK | date = 1985 | title = Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. II. Substrate interaction and product inhibition studies of flavonol 3-, 6-, and 4'-O-methyltransferases | journal = Arch. Biochem. Biophys.  | volume = 238 | pages = 606&ndash;18  | pmid = 3994394 | doi = 10.1016/0003-9861(85)90206-1 | issue = 2 }}
* {{cite journal |author1 = Ibrahim RK |author2 =De Luca V | date = 1982 | title = Polymethylated flavonol synthesis is catalyzed by distinct O-methyltransferases | journal = Naturwissenschaften  | volume = 69 | issue = 1 | pages = 41&ndash;42 | doi = 10.1007/BF00441101 }}

{{One carbon transferases}}
{{Enzymes}}
{{Portal bar|Biology|border=no}}

[[Category:EC 2.1.1]]
[[Category:Enzymes of unknown structure]]
[[Category:Quercetin]]
[[Category:Flavonols metabolism]]
[[Category:O-methylated flavonoids metabolism]]


{{2.1-enzyme-stub}}