8gk3
From Proteopedia
Cytochrome P450 3A7 in complex with Dehydroepiandrosterone sulfate
Structural highlights
FunctionCP3A7_HUMAN A cytochrome P450 monooxygenase involved in the metabolism of steroid hormones and vitamins during embryogenesis (PubMed:9555064, PubMed:11093772, PubMed:14559847, PubMed:12865317, PubMed:17178770). 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) (PubMed:9555064, PubMed:11093772, PubMed:14559847, PubMed:12865317, PubMed:17178770). Catalyzes the hydroxylation of carbon-hydrogen bonds. Metabolizes 3beta-hydroxyandrost-5-en-17-one (dehydroepiandrosterone, DHEA), a precursor in the biosynthesis of androgen and estrogen steroid hormones (PubMed:9555064, PubMed:17178770). Exhibits high catalytic activity for the formation of hydroxyestrogens from estrone (E1), particularly D-ring hydroxylated estrone at the C16-alpha position (PubMed:14559847, PubMed:12865317). Mainly hydroxylates all trans-retinoic acid (atRA) to 4-hydroxyretinoate and may play a role in atRA clearance during fetal development (PubMed:11093772). Also involved in the oxidative metabolism of xenobiotics including anticonvulsants (PubMed:9555064).[1] [2] [3] [4] [5] Publication Abstract from PubMedHuman fetal cytochrome P450 3A7 (CYP3A7) is involved in both xenobiotic metabolism and the estriol biosynthetic pathway. Although much is understood about cytochrome P450 3A4 (CYP3A4) and its role in adult drug metabolism, CYP3A7 is poorly characterized in terms of its interactions with both categories of substrates. Herein, a crystallizable mutated form of CYP3A7 was saturated with its primary endogenous substrate dehydroepiandrosterone 3-sulfate (DHEA-S) to yield a 2.6 A X-ray structure revealing the unexpected capacity to simultaneously bind four copies of DHEA-S. Two DHEA-S molecules are located in the active site proper, one in a ligand access channel, and one on the hydrophobic F'-G' surface normally embedded in the membrane. While neither DHEA-S binding or metabolism exhibit cooperative kinetics, the current structure is consistent with cooperativity common to CYP3A enzymes. Overall, this information suggests that mechanism(s) of CYP3A7 interactions with steroidal substrates are complex. Human Cytochrome P450 3A7 Binding Four Copies of Its Native Substrate Dehydroepiandrosterone 3-Sulfate.,Liu J, Kandel SE, Lampe JN, Scott EE J Biol Chem. 2023 Jun 29:104993. doi: 10.1016/j.jbc.2023.104993. PMID:37392852[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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