3-Beta-Hydroxysteroid Dehydrogenase Type 3 (HSD3b3)

HSD3b3 belongs to the 3-beta-HSD family. Tissue specificity Liver and kidney. Greater expression in liver. 3-beta-HSD is a bifunctional enzyme, that catalyzes the oxidative conversion of Delta(5)-ene-3-beta-hydroxy steroid, and the oxidative conversion of ketosteroids. The 3-beta-HSD enzymatic system plays a crucial role in the biosynthesis of all classes of hormonal steroids.

3-β-HSD is an enzyme that catalyses the synthesis of progesterone from pregnenolone, 17-hydroxyprogesterone from 17-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone in the adrenal gland. It is the only enzyme in the adrenal pathway of corticosteroid synthesis that is not a member of the Cytochrome P450 family. In humans, there are two 3-β-HSD isozymes encoded by the HSD3B1 and HSD3B2 genes, respectively.