Reaction: (1) cholest-5-ene-3β,25-diol + NADPH + H+ + O2 = cholest-5-ene-3β,7α,25-triol + NADP+ + H2O
(2) (25R)-cholest-5-ene-3β,26-diol + NADPH + H+ + O2 = (25R)-cholest-5-ene-3β,7α,26-triol + NADP+ + H2O
For diagram of reaction, click here
Other name(s): 25-hydroxycholesterol 7α-monooxygenase; CYP7B1; CYP7B1 oxysterol 7α-hydroxylase; 27-hydroxycholesterol 7-monooxygenase; 27-hydroxycholesterol 7α-hydroxylase; cholest-5-ene-3β,25-diol,NADPH:oxygen oxidoreductase (7α-hydroxylating); 25-hydroxycholesterol 7α-hydroxylase
Systematic name: cholest-5-ene-3β,25/26-diol,NADPH:oxygen oxidoreductase (7α-hydroxylating)
Comments: A heme-thiolate protein (P-450). Unlike EC 18.104.22.168, 24-hydroxycholesterol 7α-monooxygenase, which is specific for its oxysterol substrate, this enzyme can also metabolize the oxysterols 24,25-epoxycholesterol, 22-hydroxycholesterol and 24-hydroxycholesterol, but to a lesser extent .
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 149316-80-3
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