Flavonoid 3',5'-hydroxylase explained

Flavonoid 3',5'-hydroxylase
Ec Number:	1.14.14.81
Cas Number:	94047-23-1

Flavonoid 3',5'-hydroxylase (was wrongly classified as in the past) is an enzyme with systematic name flavanone,NADPH:oxygen oxidoreductase.^{[1] [2] [3]} This enzyme catalyses the following chemical reaction

flavanone + 2 NADPH + 2 H⁺ + 2 O₂

\rightleftharpoons 3',5'-dihydroxyflavanone + 2 NADP⁺ + 2 H₂O (overall reaction)

(1a) flavanone + NADPH + H⁺ + O₂

\rightleftharpoons 3'-hydroxyflavanone + NADP⁺ + H₂O

(1b) 3'-hydroxyflavanone + NADPH + H⁺ + O₂

\rightleftharpoons 3',5'-dihydroxyflavanone + NADP⁺ + H₂O

Flavonoid 3',5'-hydroxylase is a heme-thiolate protein (P-450).

Notes and References

1. Menting J, Scopes RK, Stevenson TW . Characterization of Flavonoid 3[prime],5[prime]-Hydroxylase in Microsomal Membrane Fraction of Petunia hybrida Flowers . Plant Physiology . 106 . 2 . 633–642 . October 1994 . 12232356 . 159570 . 10.1104/pp.106.2.633 .
2. Shimada Y, Nakano-Shimada R, Ohbayashi M, Okinaka Y, Kiyokawa S, Kikuchi Y . Expression of chimeric P450 genes encoding flavonoid-3', 5'-hydroxylase in transgenic tobacco and petunia plants(1) . FEBS Letters . 461 . 3 . 241–5 . November 1999 . 10567704 . 10.1016/s0014-5793(99)01425-8 . free .
3. de Vetten N, ter Horst J, van Schaik HP, de Boer A, Mol J, Koes R . A cytochrome b5 is required for full activity of flavonoid 3', 5'-hydroxylase, a cytochrome P450 involved in the formation of blue flower colors . Proceedings of the National Academy of Sciences of the United States of America . 96 . 2 . 778–83 . January 1999 . 9892710 . 15213 . 10.1073/pnas.96.2.778 . free .