3-beta hydroxy-5-ene steroid dehydrogenase type 1; steroid delta isomerase; progesterone reductase (HSD3B1, HSDB3A)

Function

• biosynthesis of all classes of hormonal steroids
• bifunctional enzyme
• catalyzes oxidative conversion of delta(5)-ene-3-beta-hydroxy steroid, & oxidative conversion of ketosteroids

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

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

Structure

belongs to the 3-beta-HSD family

Compartment

• endoplasmic reticulum membrane
• mitochondrial membrane

Expression

• placenta & skin
• predominantly expressed in mammary gland tissue

More general terms

• dehydrogenase
• isomerase
• mitochondrial membrane protein

Database

• UniProt: http://www.uniprot.org/uniprot/P14060.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3283
• OMIM: https://mirror.omim.org/entry/109715