AF123: Isoflavone reductase family

List allergens from this family:

Routes of exposure:
Include only IUIS approved allergens.

Biochemical properties

This family contains different NADP-dependent oxidoreductases involved in plant secondary metabolism, as there are isoflavone reductases, phenylcoumaran benzylic ether reductases, and pinoresinol-lariciresinol reductases [1]. Another family member is NmrA, a negative transcriptional regulator involved in the post-translational modification of the transcription factor AreA. NmrA is part of a system controlling nitrogen metabolite repression in fungi [2].

Allergens from this family

Allergens from this family include the minor birch pollen allergen Bet v 6, which was shown to cross-react with homologous proteins from plant food [3], and an allergen from Japanese cedar pollen [4].



  1. Min T, Kasahara H, Bedgar DL, Youn B, Lawrence PK, Gang DR, Halls SC, Park H, Hilsenbeck JL, Davin LB, Lewis NG, Kang C:
    Crystal structures of pinoresinol-lariciresinol and phenylcoumaran benzylic ether reductases and their relationship to isoflavone reductases.
    J Biol Chem 2003, 278, 50714-23. [PubMed] [Full Text]
  2. Stammers DK, Ren J, Leslie K, Nichols CE, Lamb HK, Cocklin S, Dodds A, Hawkins AR:
    The structure of the negative transcriptional regulator NmrA reveals a structural superfamily which includes the short-chain dehydrogenase/reductases.
    EMBO J 2001, 20, 6619-26. [PubMed] [Full Text]
  3. Karamloo F, Wangorsch A, Kasahara H, Davin LB, Haustein D, Lewis NG, Vieths S:
    Phenylcoumaran benzylic ether and isoflavonoid reductases are a new class of cross-reactive allergens in birch pollen, fruits and vegetables.
    Eur J Biochem 2001, 268, 5310-20. [PubMed]
  4. Kawamoto S, Fujimura T, Nishida M, Tanaka T, Aki T, Masubuchi M, Hayashi T, Suzuki O, Shigeta S, Ono K:
    Molecular cloning and characterization of a new Japanese cedar pollen allergen homologous to plant isoflavone reductase family.
    Clin Exp Allergy 2002, 32, 1064-70. [PubMed]


Links to Pfam

Family-defining Pfam domains (at least one of these domains is present in each family member):

Pfam domain Pfam clan
PF05368 NmrA-like family CL0063 FAD/NAD(P)-binding Rossmann fold Superfamily


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