| Function | A cytochrome P450 monooxygenase involved in corticoid and androgen biosynthesis. Catalyzes 17-alpha hydroxylation of C21 steroids, which is common for both pathways. A second oxidative step, required only for androgen synthesis, involves an acyl-carbon cleavage. The 17-alpha hydroxy intermediates, as part of adrenal glucocorticoids biosynthesis pathway, are precursors of cortisol (Probable). Hydroxylates steroid hormones, pregnenolone and progesterone to form 17-alpha hydroxy metabolites, followed by the cleavage of the C17-C20 bond to form C19 steroids, dehydroepiandrosterone (DHEA) and androstenedione. Has 16-alpha hydroxylase activity. Catalyzes 16-alpha hydroxylation of 17-alpha hydroxy pregnenolone, followed by the cleavage of the C17-C20 bond to form 16-alpha-hydroxy DHEA. Also 16-alpha hydroxylates androgens, relevant for estriol synthesis. 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). |
| Protein Name | Steroid 17-Alpha-Hydroxylase/17 -20 Lyase17-Alpha-Hydroxyprogesterone AldolaseCypxviiCytochrome P450 17a1Cytochrome P450-C17Cytochrome P450c17Steroid 17-Alpha-Monooxygenase |
| Database Links | Reactome: R-HSA-193048Reactome: R-HSA-194002Reactome: R-HSA-5579028 |
| Cellular Localisation | Endoplasmic Reticulum MembraneMicrosome Membrane |
| Alternative Protein Names | Steroid 17-Alpha-Hydroxylase/17 -20 Lyase protein17-Alpha-Hydroxyprogesterone Aldolase proteinCypxvii proteinCytochrome P450 17a1 proteinCytochrome P450-C17 proteinCytochrome P450c17 proteinSteroid 17-Alpha-Monooxygenase proteinCYP17A1 proteinCYP17 proteinS17AH protein |
Information sourced from Uniprot.org
