KEGG   ENZYME: 1.14.13.136Help
Entry
EC 1.14.13.136              Enzyme                                 

Name
2-hydroxyisoflavanone synthase;
CYP93C;
IFS;
isoflavonoid synthase
Class
Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With NADH or NADPH as one donor, and incorporation of one atom of oxygen into the other donor
BRITE hierarchy
Sysname
liquiritigenin,NADPH:oxygen oxidoreductase (hydroxylating, aryl migration)
Reaction(IUBMB)
(1) liquiritigenin + O2 + NADPH + H+ = 2,4',7-trihydroxyisoflavanone + H2O + NADP+ [RN:R07777];
(2) (2S)-naringenin + O2 + NADPH + H+ = 2,4',5,7-tetrahydroxyisoflavanone + H2O + NADP+ [RN:R07778]
Reaction(KEGG)
R07777 R07778;
(other) R07715
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Substrate
liquiritigenin [CPD:C09762];
O2 [CPD:C00007];
NADPH [CPD:C00005];
H+ [CPD:C00080];
(2S)-naringenin [CPD:C00509]
Product
2,4',7-trihydroxyisoflavanone;
H2O [CPD:C00001];
NADP+ [CPD:C00006];
2,4',5,7-tetrahydroxyisoflavanone
Comment
Requires cytochrome P-450. The reaction involves the migration of the 2-phenyl group of the flavanone to the 3-position of the isoflavanone. The 2-hydroxyl group is derived from the oxygen molecule. EC 4.2.1.105, 2-hydroxyisoflavanone dehydratase, acts on the products with loss of water and formation of genistein and daidzein, respectively.
History
EC 1.14.13.136 created 2011, modified 2013
Pathway
Isoflavonoid biosynthesis
Biosynthesis of secondary metabolites
Orthology
K13257  
2-hydroxyisoflavanone synthase
Genes
GMX: 
100037450(IFS1) 606705(IFS2)
CAM: 
101495474(cyp93C3)
Taxonomy
Reference
1  [PMID:3956488]
  Authors
Kochs G, Grisebach H.
  Title
Enzymic synthesis of isoflavones.
  Journal
Eur. J. Biochem. 155 (1986) 311-8.
Reference
2  [PMID:2226805]
  Authors
Hashim MF, Hakamatsuka T, Ebizuka Y, Sankawa U
  Title
Reaction mechanism of oxidative rearrangement of flavanone in isoflavone biosynthesis.
  Journal
FEBS. Lett. 271 (1990) 219-22.
Reference
3  [PMID:10375412]
  Authors
Steele CL, Gijzen M, Qutob D, Dixon RA.
  Title
Molecular characterization of the enzyme catalyzing the aryl migration reaction of isoflavonoid biosynthesis in soybean.
  Journal
Arch. Biochem. Biophys. 367 (1999) 146-50.
  Sequence
[gmx:606705]
Reference
4  [PMID:12207646]
  Authors
Sawada Y, Kinoshita K, Akashi T, Aoki T, Ayabe S
  Title
Key amino acid residues required for aryl migration catalysed by the cytochrome P450 2-hydroxyisoflavanone synthase.
  Journal
Plant. J. 31 (2002) 555-64.
  Sequence
Reference
5  [PMID:15809082]
  Authors
Sawada Y, Ayabe S
  Title
Multiple mutagenesis of P450 isoflavonoid synthase reveals a key active-site residue.
  Journal
Biochem. Biophys. Res. Commun. 330 (2005) 907-13.
  Sequence
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 

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