View source for Homocysteine S-methyltransferase

{{enzyme
| Name = isoflavone 4'-O-methyltransferase
| EC_number = 2.1.1.46
| CAS_number = 55071-80-2
| IUBMB_EC_number = 2/1/1/46
| GO_code = 0030746
| image = 
| width = 
| caption = 
}}
In [[enzymology]], an '''isoflavone 4'-O-methyltransferase''' ({{EC number|2.1.1.46}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:S-adenosyl-L-methionine + an isoflavone <math>\rightleftharpoons</math> S-adenosyl-L-homocysteine + a 4'-O-methylisoflavone

Thus, the two [[substrate (biochemistry)|substrates]] of this enzyme are [[S-Adenosyl methionine|S-adenosyl methionine]] and [[isoflavone]], whereas its two [[product (chemistry)|products]] are [[S-adenosylhomocysteine]] and [[4'-O-methylisoflavone]].

This enzyme belongs to the family of [[transferase]]s, specifically those transferring one-carbon group methyltransferases.  The systematic name of this enzyme class is '''S-adenosyl-L-methionine:isoflavone 4'-O-methyltransferase'''. Other names in common use include '''4'-hydroxyisoflavone methyltransferase''', '''isoflavone methyltransferase''', and '''isoflavone O-methyltransferase'''.  This enzyme participates in [[isoflavonoid biosynthesis]].  

== References ==
{{reflist|1}}
* {{cite journal | author = Wengenmayer H, Ebel J, Grisebach H | date = 1974 | title = Purification and properties of a S-adenosylmethionine: isoflavone 4'-O-methyltransferase from cell suspension cultures of Cicer arietinum L | journal = Eur. J. Biochem.  | volume = 50 | pages = 135&ndash;43  | pmid = 4452353 | doi = 10.1111/j.1432-1033.1974.tb03881.x | issue = 1 }}

{{transferase-stub}}

[[Category:EC 2.1.1]]
[[Category:Enzymes of unknown structure]]
[[Category:Isoflavonoids metabolism]]
[[Category:O-Methylated flavonoids metabolism]]