Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

5.3.3.1

RLRdb entry

RL00033

Organisms

Homo sapiens (Human) (9606_human)

Synonyms

3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 2;
3-beta-HSD II;
3-beta-hydroxy-Delta(5)-steroid dehydrogenase;
EC=1.1.1.145;
3-beta-hydroxy-5-ene steroid dehydrogenase;
Progesterone reductase;
Steroid Delta-isomerase;
EC=5.3.3.1;
Delta-5-3-ketosteroid isomerase;

Key words

Congenital adrenal hyperplasia, Disease mutation, Endoplasmic reticulum, Isomerase, Membrane, Mitochondrion, Multifunctional enzyme, NAD, Oxidoreductase, Polymorphism, Steroidogenesis, Transmembrane

Links to iHOP

P26439

Function

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.

Subcellular localization

Endoplasmic reticulum membrane; Single-pass membrane protein. Mitochondrion membrane; Single-pass membrane protein

Catalytic activity

A 3-oxo-Delta(5)-steroid = a 3-oxo-Delta(4)-steroid
A 3-beta-hydroxy-Delta(5)-steroid + NAD(+) = a 3-oxo-Delta(5)-steroid + NADH

Gene ontology

F:binding
F:3-beta-hydroxy-delta5-steroid dehydrogenase...
F:steroid delta-isomerase activity
P:oxidation reduction
C:microsome
C:mitochondrial intermembrane space
C:integral to membrane
C:smooth endoplasmic reticulum membrane
P:C21-steroid hormone biosynthetic process
C:mitochondrial inner membrane

Tissue specificity

Adrenal glands, testes and ovaries.

Disease

Mild HSD3B2 deficiency in hyperandrogenic females is associated with characteristic traits of polycystic ovary syndrome, such as insulin resistance and luteinizing hormon hypersecretion
Defects in HSD3B2 are the cause of adrenal hyperplasia type 2 (AH2) [MIM:201810]. AH2 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). In AH2, virilization is much less marked or does not occur. AH2 is frequently lethal in early life.

Fasta

>P26439 : length: 372
MGWSCLVTGAGGLLGQRIVRLLVEEKELKEIRALDKAFRPELREEFSKLQNRTKLTVLEG
DILDEPFLKRACQDVSVVIHTACIIDVFGVTHRESIMNVNVKGTQLLLEACVQASVPVFI
YTSSIEVAGPNSYKEIIQNGHEEEPLENTWPTPYPYSKKLAEKAVLAANGWNLKNGDTLY
TCALRPTYIYGEGGPFLSASINEALNNNGILSSVGKFSTVNPVYVGNVAWAHILALRALR
DPKKAPSVRGQFYYISDDTPHQSYDNLNYILSKEFGLRLDSRWSLPLTLMYWIGFLLEVV
SFLLSPIYSYQPPFNRHTVTLSNSVFTFSYKKAQRDLAYKPLYSWEEAKQKTVEWVGSLV
DRHKETLKSKTQ



  Copyright 2009, Center for Bioinformatics 
  Last Modified: 2009-03-24  
  Design by Zhao Min