Molecular cloning and biochemical characterization of a novel cytochrome P450, flavone synthase II, that catalyzes direct conversion of flavanones to flavones

Plant Cell Physiol. 1999 Nov;40(11):1182-6. doi: 10.1093/oxfordjournals.pcp.a029505.


Cytochrome P450 cDNAs, AFNS2 and TFNS5, were isolated from snapdragon and torenia petal cDNA libraries, respectively, based on the sequence homology with licorice CYP93B1 cDNA encoding (2S)-flavanone 2-hydroxylase. They were expressed in yeast and identified to encode flavone synthase II catalyzing direct conversion of flavanones to flavones probably via 2-hydroxyflavanones.

MeSH terms

  • Amino Acid Sequence
  • Catalysis
  • Cloning, Molecular
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism*
  • Flavonoids / biosynthesis*
  • Flavonoids / metabolism*
  • Mixed Function Oxygenases / genetics*
  • Mixed Function Oxygenases / metabolism*
  • Molecular Sequence Data
  • Phylogeny
  • Plants / enzymology
  • Plants / genetics
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Substrate Specificity


  • Flavonoids
  • Recombinant Proteins
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases
  • cytochrome P-450 CYP93B1 (Glycyrrhiza echinata)

Associated data

  • GENBANK/AB028151
  • GENBANK/AB028152