FAD-dependent urate hydroxylase explained

FAD-dependent urate hydroxylase
Ec Number:	1.14.13.113

FAD-dependent urate hydroxylase (HpxO enzyme, FAD-dependent urate oxidase, urate hydroxylase) is an enzyme with systematic name urate,NADH:oxygen oxidoreductase (5-hydroxyisourate forming).^{[1] [2]} A non-homologous isofunctional enzyme (NISE) to HpxO was found, and named HpyO.^[3] HpyO was determined to be a typical Michaelian enzyme. These FAD-dependent urate hydroxylases are flavoproteins.

This enzyme catalyses the following chemical reaction

urate + FADH + H⁺ + O₂

\rightleftharpoons 5-hydroxyisourate + FAD⁺ + H₂O

Notes and References

1. Biochemical characterization of the HpxO enzyme from Klebsiella pneumoniae, a novel FAD-dependent urate oxidase . O'Leary, S.E. . Hicks, K.A. . Ealick, S.E. . Begley, T.P. . Biochemistry . 2009 . 48 . 3033–3035 . 19260710 . 10.1021/bi900160b . 14 . 2842088.
2. The hpx genetic system for hypoxanthine assimilation as a nitrogen source in Klebsiella pneumoniae: gene organization and transcriptional regulation . de la Riva L . Badia J . Aguilar J . Bender RA . Baldoma L. . Journal of Bacteriology . 2008 . 190 . 7892–7903 . 18849434 . 10.1128/JB.01022-08 . 24 . 2593211.
3. Microbial urate catabolism: characterization of HpyO, a non-homologous isofunctional isoform of the flavoprotein urate hydroxylase HpxO . Michiel M, Perchat N, Perret A, Tricot S, Papeil A, Besnard M, de Berardinis V, Salanoubat M, Fischer C . Environmental Microbiology Reports . 2012 . 4 . 642–647 . 23760935 . 10.1111/j.1758-2229.2012.00390.x . 6. free .