Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With reduced iron-sulfur protein as one donor, and incorporation of one atom of oxygen into the other donor
This mitochondrial cytochrome P-450 enzyme requires adrenodoxin. The enzyme can perform up to 6 rounds of hydroxylation of the substrate calcitriol leading to calcitroic acid. The human enzyme also shows 23-hydroxylating activity leading to 1,25 dihydroxyvitamin D3-26,23-lactone as end product while the mouse and rat enzymes do not. The initial source of the electrons is NADPH, which transfers the electrons to the adrenodoxin via EC 1.18.1.6, adrenodoxin-NADP+ reductase.
History
EC 1.14.15.16 created 2011 as EC 1.14.13.126, transferred 2016 to EC 1.14.15.16
Masuda S, Strugnell SA, Knutson JC, St-Arnaud R, Jones G
Title
Evidence for the activation of 1alpha-hydroxyvitamin D2 by 25-hydroxyvitamin D-24-hydroxylase: delineation of pathways involving 1alpha,24-dihydroxyvitamin D2 and 1alpha,25-dihydroxyvitamin D2.
Hamamoto H, Kusudo T, Urushino N, Masuno H, Yamamoto K, Yamada S, Kamakura M, Ohta M, Inouye K, Sakaki T
Title
Structure-function analysis of vitamin D 24-hydroxylase (CYP24A1) by site-directed mutagenesis: amino acid residues responsible for species-based difference of CYP24A1 between humans and rats.