Cholest-5-ene-3beta,7alpha-diol 3beta-dehydrogenase

cholest-5-ene-3β,7α-diol 3β-dehydrogenase
Identifiers
EC number	1.1.1.181
CAS number	56626-16-5
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles

hydroxy-Δ-5-steroid dehydrogenase, 3β- and steroid Δ-isomerase 7
Identifiers
Symbol	HSD3B7
Entrez	80270
HUGO	18324
OMIM	607764
RefSeq	NM_025193
UniProt	Q9H2F3
Other data
EC number	1.1.1.181
Locus	Chr. 16 p11.2

In enzymology, a cholest-5-ene-3β,7α-diol 3β-dehydrogenase (EC 1.1.1.181) is an enzyme that catalyzes the chemical reaction:^[1]

cholest-5-ene-3β,7α-diol + NAD⁺ $\rightleftharpoons$ 7α-hydroxycholest-4-en-3-one + NADH + H⁺

Thus, the two substrates of this enzyme are cholest-5-ene-3β,7α-diol and NAD⁺, whereas its 3 products are 7α-hydroxycholest-4-en-3-one, NADH, and H⁺.

The systematic name of this enzyme class is cholest-5-ene-3β,7α-diol:NAD+ 3-oxidoreductase. This enzyme is also called 3β-hydroxy-Δ5-C27-steroid oxidoreductase. The human version of this enzyme is known as hydroxy-Δ-5-steroid dehydrogenase, 3 β- and steroid delta-isomerase 7 or HSD3B7 which is encoded by the HSD3B7 gene.^[2][3]

Function

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. This enzyme is involved in the initial stages of the synthesis of bile acids from cholesterol and a member of the short-chain dehydrogenase/reductase superfamily. This enzyme is a membrane-associated endoplasmic reticulum protein which is active against 7-alpha hydrosylated sterol substrates.^[4]

Clinical significance

Mutations in the HSD3B7 gene are associated with a congenital bile acid synthesis defect which leads to neonatal cholestasis, a form of progressive liver disease.^[4]

See also

• 3-beta-HSD

References

1. ^ Wikvall K (April 1981). "Purification and properties of a 3 β-hydroxy-delta 5-C27-steroid oxidoreductase from rabbit liver microsomes". J. Biol. Chem. 256 (7): 3376–80. PMID 6937465. 
2. ^ Schwarz M, Wright AC, Davis DL, Nazer H, Björkhem I, Russell DW (November 2000). "The bile acid synthetic gene 3β-hydroxy-Δ(5)-C(27)-steroid oxidoreductase is mutated in progressive intrahepatic cholestasis". J. Clin. Invest. 106 (9): 1175–84. doi:10.1172/JCI10902. PMC 301421. PMID 11067870. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=301421. 
3. ^ Persson B, Kallberg Y, Bray JE, Bruford E, Dellaporta SL, Favia AD, Duarte RG, Jörnvall H, Kavanagh KL, Kedishvili N, Kisiela M, Maser E, Mindnich R, Orchard S, Penning TM, Thornton JM, Adamski J, Oppermann U (March 2009). "The SDR (short-chain dehydrogenase/reductase and related enzymes) nomenclature initiative". Chem. Biol. Interact. 178 (1–3): 94–8. doi:10.1016/j.cbi.2008.10.040. PMC 2896744. PMID 19027726. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2896744. 
4. ^ ^{a b} "Entrez Gene: HSD3B7". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=80270. 

This article incorporates text from the United States National Library of Medicine, which is in the public domain.