Rat Cytochrome P450 7A1,CYP7A1 ELI

A cytochrome P450 monooxygenase involved in the metabolism of endogenous cholesterol and its oxygenated derivatives (oxysterols) (PubMed:1694852, PubMed:2335522).

Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH-ferrihemoprotein reductase) (PubMed:1694852, PubMed:2335522).

Functions as a critical regulatory enzyme of bile acid biosynthesis and cholesterol homeostasis.

Catalyzes the hydroxylation of carbon hydrogen bond at 7-alpha position of cholesterol, a rate-limiting step in cholesterol catabolism and bile acid biosynthesis (PubMed:1694852, PubMed:2335522).

7-alpha hydroxylates several oxysterols, including 4beta-hydroxycholesterol and 24-hydroxycholesterol.

Catalyzes the oxidation of the 7,8 double bond of 7-dehydrocholesterol and lathosterol with direct and predominant formation of the 7-keto derivatives (By similarity).

{ECO:0000250|UniProtKB:P22680, ECO:0000269|PubMed:1694852, ECO:0000269|PubMed:2335522}.