A cytochrome P450 monooxygenase involved in the metabolism of sterols, steroid hormones, retinoids and fatty acids (PubMed:10681376, PubMed:11093772, PubMed:11555828, PubMed:14559847, PubMed:12865317, PubMed:15373842, PubMed:15764715, PubMed:20702771, PubMed:19965576, PubMed:21490593, PubMed:21576599). 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 (NADPH--hemoprotein reductase). Catalyzes the hydroxylation of carbon-hydrogen bonds (PubMed:2732228, PubMed:14559847, PubMed:12865317, PubMed:15373842, PubMed:15764715, PubMed:21576599, PubMed:21490593). Exhibits high catalytic activity for the formation of hydroxyestrogens from estrone (E1) and 17beta-estradiol (E2), namely 2-hydroxy E1 and E2, as well as D-ring hydroxylated E1 and E2 at the C-16 position (PubMed:11555828, PubMed:14559847, PubMed:12865317). Plays a role in the metabolism of androgens, particularly in oxidative deactivation of testosterone (PubMed:2732228, PubMed:15373842, PubMed:15764715, PubMed:22773874). Metabolizes testosterone to less biologically active 2beta- and 6beta-hydroxytestosterones (PubMed:2732228, PubMed:15373842, PubMed:15764715). Contributes to the formation of hydroxycholesterols (oxysterols), particularly A-ring hydroxylated cholesterol at the C-4beta position, and side chain hydroxylated cholesterol at the C-25 position, likely contributing to cholesterol degradation and bile acid biosynthesis (PubMed:21576599). Catalyzes bisallylic hydroxylation of polyunsaturated fatty acids (PUFA) (PubMed:9435160). Catalyzes the epoxidation of double bonds of PUFA with a preference for the last double bond (PubMed:19965576). Metabolizes endocannabinoid arachidonoylethanolamide (anandamide) to 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EpETrE-EAs), potentially modulating endocannabinoid system signaling (PubMed:20702771). Plays a role in the metabolism of retinoids. Displays high catalytic activity for oxidation of all-trans-retinol to all-trans-retinal, a rate-limiting step for the biosynthesis of all-trans-retinoic acid (atRA) (PubMed:10681376). Further metabolizes atRA toward 4-hydroxyretinoate and may play a role in hepatic atRA clearance (PubMed:11093772). Responsible for oxidative metabolism of xenobiotics. Acts as a 2-exo-monooxygenase for plant lipid 1,8-cineole (eucalyptol) (PubMed:11159812). Metabolizes the majority of the administered drugs. Catalyzes sulfoxidation of the anthelmintics albendazole and fenbendazole (PubMed:10759686). Hydroxylates antimalarial drug quinine (PubMed:8968357). Acts as a 1,4-cineole 2-exo-monooxygenase (PubMed:11695850). Also involved in vitamin D catabolism and calcium homeostasis. Catalyzes the inactivation of the active hormone calcitriol (1-alpha,25-dihydroxyvitamin D(3)) (PubMed:29461981). an organic molecule + O2 + reduced [NADPH--hemoprotein reductase] = an alcohol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-estradiol + O2 + reduced [NADPH--hemoprotein reductase] = 2-hydroxy-17beta-estradiol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-estradiol + O2 + reduced [NADPH--hemoprotein reductase] = 4-hydroxy-17beta-estradiol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-estradiol + O2 + reduced [NADPH--hemoprotein reductase] = 16alpha,17beta-estriol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-estradiol + O2 + reduced [NADPH--hemoprotein reductase] = 16beta,17beta-estriol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] estrone + O2 + reduced [NADPH--hemoprotein reductase] = 2-hydroxyestrone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] estrone + O2 + reduced [NADPH--hemoprotein reductase] = 4-hydroxyestrone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] estrone + O2 + reduced [NADPH--hemoprotein reductase] = 16alpha-hydroxyestrone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 1beta-hydroxytestosterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 2beta-hydroxytestosterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 6beta,17beta-dihydroxyandrost-4-en-3-one + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 11beta,17beta-dihydroxyandrost-4-ene-3-one + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-hydroxy-5alpha-androstan-3-one + O2 + reduced [NADPH--hemoprotein reductase] = 17beta,18-dihydroxy-3-oxo-5alpha-androstanone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-hydroxy-5alpha-androstan-3-one + O2 + reduced [NADPH--hemoprotein reductase] = 17beta,19-dihydroxy-3-oxo-5alpha-androstanone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] androst-4-ene-3,17-dione + O2 + reduced [NADPH--hemoprotein reductase] = 6beta-hydroxyandrost-4-ene-3,17-dione + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + progesterone + reduced [NADPH--hemoprotein reductase] = 6beta-hydroxyprogesterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + progesterone + reduced [NADPH--hemoprotein reductase] = 16alpha-hydroxyprogesterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cortisone + O2 + reduced [NADPH--hemoprotein reductase] = 6beta-hydroxycortisone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cortisol + O2 + reduced [NADPH--hemoprotein reductase] = 6beta-hydroxycortisol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cholesterol + O2 + reduced [NADPH--hemoprotein reductase] = 25-hydroxycholesterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cholesterol + O2 + reduced [NADPH--hemoprotein reductase] = 4beta-hydroxycholesterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cholesterol + O2 + reduced [NADPH--hemoprotein reductase] = (22R)-hydroxycholesterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cholesterol + O2 + reduced [NADPH--hemoprotein reductase] = (24R)-hydroxycholesterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] cholesterol + O2 + reduced [NADPH--hemoprotein reductase] = 26-hydroxycholesterol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (9Z,12Z)-octadecadienoate + O2 + reduced [NADPH--hemoprotein reductase] = 11-hydroxy-(9Z,12Z)-octadecadienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 7-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 10-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 13-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (14R,15S)-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (14S,15R)-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate + O2 + reduced [NADPH--hemoprotein reductase] = (17R,18S)-epoxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (4Z,7Z,10Z,13Z,16Z,19Z)-docosahexaenoate + O2 + reduced [NADPH--hemoprotein reductase] = (19R,20S)-epoxy-(4Z,7Z,10Z,13Z,16Z)-docosapentaenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (4Z,7Z,10Z,13Z,16Z,19Z)-docosahexaenoate + O2 + reduced [NADPH--hemoprotein reductase] = (19S,20R)-epoxy-(4Z,7Z,10Z,13Z,16Z)-docosapentaenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] N-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-ethanolamine + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + H2O + N-(8,9-epoxy-5Z,11Z,14Z-eicosatrienoyl)-ethanolamine + oxidized [NADPH--hemoprotein reductase] N-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-ethanolamine + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + H2O + N-(11,12-epoxy-5Z,8Z,14Z-eicosatrienoyl)-ethanolamine + oxidized [NADPH--hemoprotein reductase] N-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-ethanolamine + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + H2O + N-(14,15-epoxy-5Z,8Z,11Z-eicosatrienoyl)-ethanolamine + oxidized [NADPH--hemoprotein reductase] all-trans-retinol + O2 + reduced [NADPH--hemoprotein reductase] = all-trans-retinal + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] all-trans-retinoate + O2 + reduced [NADPH--hemoprotein reductase] = all-trans-4-hydroxyretinoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + quinine + reduced [NADPH--hemoprotein reductase] = 3-hydroxyquinine + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] fenbendazole + O2 + reduced [NADPH--hemoprotein reductase] = fenbendazole S-oxide + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] albendazole + O2 + reduced [NADPH--hemoprotein reductase] = albendazole S-oxide + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 1,8-cineole + O2 + reduced [NADPH--hemoprotein reductase] = 2-exo-hydroxy-1,8-cineole + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 1,4-cineole + O2 + reduced [NADPH--hemoprotein reductase] = 2-exo-hydroxy-1,4-cineole + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Activated by cytochrome b5. Steroid hormone biosynthesis. Cofactor metabolism; retinol metabolism. Steroid metabolism; cholesterol metabolism. Lipid metabolism; fatty acid metabolism. Interacts with PGRMC1; the interaction requires PGRMC1 homodimerization. Expressed in prostate and liver. According to some authors, it is not expressed in brain (PubMed:19094056). According to others, weak levels of expression are measured in some brain locations (PubMed:19359404 and PubMed:18545703). Also expressed in epithelium of the small intestine and large intestine, bile duct, nasal mucosa, kidney, adrenal cortex, epithelium of the gastric mucosa with intestinal metaplasia, gallbladder, intercalated ducts of the pancreas, chief cells of the parathyroid and the corpus luteum of the ovary (at protein level). By drugs, such as rifampicin. Polyubiquitinated in the presence of AMFR and UBE2G1 and also STUB1/CHIP and UBE2D1 (in vitro). The gene represented in this entry is involved in disease pathogenesis. Chimeric transcripts, characterized by CYP3A43 exon 1 joined at canonical splice sites to distinct sets of CYP3A4 exons, have been detected. All are possibly produced by trans-splicing. The chimeric transcripts exist in 3 different combinations: CYP3A43 exon 1 joined in frame to CYP3A4 exons 2-13, CYP3A43 exon 1 joined in frame to CYP3A4 exons 4-13 and CYP3A43 exon 1 joined in frame to CYP3A4 exon 7-13. The longest chimeric isoform (CYP3A43 exon 1 joined to CYP3A4 exons 2-13) exhibits 6-beta-hydroxylase activity, while a shorter isoform (CYP3A43 exon 1 joined to CYP3A4 exons 4-13) does not. All chimeric transcripts are expressed at very low levels in the liver (PubMed:11726664). Belongs to the cytochrome P450 family. CYP3A4 alleles CYP3A4 entry