catalytic activity:A 3-oxo-5-alpha-steroid + acceptor = a 3-oxo-Delta(4)-steroid + reduced acceptor.,disease:Defects in SRD5A2 are the cause of pseudovaginal perineoscrotal hypospadias (PPSH) [MIM:264600]; also known as male pseudohermaphroditism due to 5-alpha-reductase deficiency or 5-ARD deficiency. PPSH is a rare form of male pseudohermaphroditism in which affected males develop normal internal urogenital tracts but fail to develop external male structures. Individuals with PPSH have testicles and tend to have a vagina and labia, but with a small penis capable of ejaculation instead of a clitoris (this penis, however, appears to be a clitoris at birth). These individuals are normally raised as girls. However at puberty their testes will descend, their voice will deepen and they often will develop a male sexual identity. They develop only limited facial hair and will not experience male-pattern baldness. Jeffrey Eugenides won a Pulitzer prize for his 2003 novel 'Middlesex' which describes the life an individual with such a deficiency.,function:Converts testosterone (T) into 5-alpha-dihydrotestosterone (DHT) and progesterone or corticosterone into their corresponding 5-alpha-3-oxosteroids. It plays a central role in sexual differentiation and androgen physiology.,online information:5-alpha reductase entry,polymorphism:Individuals with Thr-49 have an increased risk of prostate cancer. The enzyme with Thr-49 has a higher in vitro V(max) than the Ala-49 enzyme.,similarity:Belongs to the steroid 5-alpha reductase family.,tissue specificity:Expressed in high levels in the prostate and many other androgen-sensitive tissues.,
Microsome membrane; Multi-pass membrane protein. Endoplasmic reticulum membrane ; Multi-pass membrane protein .
Expressed in high levels in the prostate and many other androgen-sensitive tissues.