EC - Isoflavone 7-O-methyltransferase

  IntEnz view ENZYME view

IntEnz Enzyme Nomenclature


Accepted name:
isoflavone 7-O-methyltransferase
Systematic name:
S-adenosyl-L-methionine:hydroxyisoflavone 7-O-methyltransferase



The enzyme from alfalfa can methylate daidzein, genistein and 6,7,4'-trihydroxyisoflavone but not flavones or flavanones.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0033800
CAS Registry Number: 136111-54-1


  1. Edwards, R. and Dixon, R.A.
    Isoflavone O-methyltransferase activities in elicitor-treated cell suspension cultures of Medicago sativa.
    Phytochemistry 30: 2597-2606 (1991).
  2. He, X.Z. and Dixon, R.A.
    Genetic manipulation of isoflavone 7-O-methyltransferase enhances biosynthesis of 4'-O-methylated isoflavonoid phytoalexins and disease resistance in alfalfa.
    Plant Cell 12: 1689-1702 (2000). [PMID: 11006341]
  3. He, X.-Z. and Dixon, R.A.
    Affinity chromatography, substrate/product specificity, and amino acid sequence analysis of an isoflavone O-methyltransferase from alfalfa (Medicago sativa L.).
    Arch. Biochem. Biophys. 336: 121-129 (1996). [PMID: 8951042]
  4. He, X.Z., Reddy, J.T. and Dixon, R.A.
    Stress responses in alfalfa (Medicago sativa L). XXII. cDNA cloning and characterization of an elicitor-inducible isoflavone 7-O-methyltransferase.
    Plant Mol. Biol. 36: 43-54 (1998). [PMID: 9484461]
  5. Liu, C.-J. and Dixon, R.A.
    Elicitor-induced association of isoflavone O-methyltransferase with endomembranes prevents the formation and 7-O-methylation of daidzein during isoflavonoid phytoalexin biosynthesis.
    Plant Cell 13: 2643-2658 (2001). [PMID: 11752378]
  6. Zubieta, C., He, X.-Z., Dixon, R.A. and Noel, J.P.
    Structures of two natural product methyltransferases reveal the basis for substrate specificity in plant O-methyltransferases.
    Nat. Struct. Biol. 8: 271-279 (2001). [PMID: 11224575]
  7. Christensen, A.B., Gregersen, P.L., Olsen, C.E. and Collinge, D.B.
    A flavonoid 7-O-methyltransferase is expressed in barley leaves in response to pathogen attack.
    Plant Mol. Biol. 36: 219-227 (1998). [PMID: 9484434]

[EC created 2003]