3-beta hydroxy-5-ene steroid dehydrogenase type 2; steroid delta isomerase; progesterone reductase (HSD3B2)

Function

• 3-beta-HSD is a bifunctional enzyme
• catalyzes the oxidative conversion of delta(5)-ene-3-beta-hydroxy steroid, & the oxidative conversion of ketosteroids
• the 3-beta-HSD enzymatic system plays a crucial role in the biosynthesis of all classes of hormonal steroids
• lipid metabolism; steroid biosynthesis

3-beta-hydroxy-delta(5)-steroid + NAD+
                <-->
3-oxo-delta(5)-steroid + NADH

3-oxo-delta(5)-steroid <--> a 3-oxo-delta(4)-steroid

Structure

belongs to the 3-beta-HSD family

Compartment

• endoplasmic reticulum membrane
• mitochondrial membrane

Expression

adrenal glands, testes & ovaries

Pathology

• defects in HSD3B2 are the cause of adrenal hyperplasia type 2
• mild HSD3B2 deficiency in hyperandrogenic females is associated with traits of polycystic ovary syndrome
  • insulin resistance
  • luteinizing hormone hypersecretion

More general terms

• dehydrogenase
• isomerase
• membrane protein

Database

• UniProt: http://www.uniprot.org/uniprot/P26439.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3284
• OMIM: https://mirror.omim.org/entry/201810