Conversion of pregnenolone and progesterone to their 17- alpha-hydroxylated products and subsequently to dehydroepiandrosterone (DHEA) and androstenedione. Catalyzes both the 17-alpha-hydroxylation and the 17,20-lyase reaction. Involved in sexual development during fetal life and at puberty. Defects in CYP17A1 are the cause of adrenal hyperplasia type 5 (AH5). AH5 is a form of congenital adrenal hyperplasia, a common recessive disease due to defective synthesis of cortisol. Congenital adrenal hyperplasia is characterized by androgen excess leading to ambiguous genitalia in affected females, rapid somatic growth during childhood in both sexes with premature closure of the epiphyses and short adult stature. Four clinical types: salt wasting (SW, the most severe type), simple virilizing (SV, less severely affected patients), with normal aldosterone biosynthesis, non-classic form or late onset (NC or LOAH), and cryptic (asymptomatic). Belongs to the cytochrome P450 family. Note: This description may include information from UniProtKB.
Molecular Function: 17-alpha-hydroxyprogesterone aldolase activity; steroid 17-alpha-monooxygenase activity; oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen; iron ion binding; heme binding
Biological Process: steroid metabolic process; response to cAMP; dibenzo-p-dioxin metabolic process; response to toxin; progesterone metabolic process; androgen biosynthetic process; response to insecticide; response to organic cyclic substance; organic acid metabolic process; response to organic substance; Leydig cell differentiation; biphenyl metabolic process; response to methylmercury; hormone biosynthetic process; response to nutrient levels; response to drug; response to retinoic acid; adrenal gland development; hippocampus development; phthalate metabolic process; male gonad development; response to herbicide; ovulation; response to acetate; response to steroid hormone stimulus; response to cytokine stimulus; response to ionizing radiation; glucocorticoid biosynthetic process; steroid biosynthetic process; phenol metabolic process
LTP: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.