Molecular Cloning and Biochemical Characterization of a Novel Cytochrome P450, Flavone Synthase II, that Catalyzes Direct Conversion of Flavanones to Flavones

Abstract
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.