View source for Cholest-5-ene-3beta,7alpha-diol 3beta-dehydrogenase

{{enzyme 
| Name = cholest-5-ene-3β,7α-diol 3β-dehydrogenase
| EC_number = 1.1.1.181 
| IUBMB_EC_number = 1/1/1/181 
| CAS_number= 56626-16-5
| GO_code = 0047016
}}
{{infobox protein
| Name = hydroxy-Δ-5-steroid dehydrogenase, 3β- and steroid Δ-isomerase 7
| caption = 
| image = 
| width = 
| HGNCid = 18324
| Symbol = HSD3B7
| AltSymbols = 
| EntrezGene = 80270
| OMIM = 607764
| RefSeq = NM_025193
| UniProt = Q9H2F3
| PDB = 
| ECnumber = 1.1.1.181
| Chromosome = 16
| Arm = p
| Band = 11.2
| LocusSupplementaryData =
}}

In [[enzymology]], a '''cholest-5-ene-3β,7α-diol 3β-dehydrogenase''' ({{EC number|1.1.1.181}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]<ref name="pmid6937465">{{cite journal | author = Wikvall K | title = Purification and properties of a 3 β-hydroxy-delta 5-C27-steroid oxidoreductase from rabbit liver microsomes | journal = J. Biol. Chem. | volume = 256 | issue = 7 | pages = 3376–80 |date=April 1981 | pmid = 6937465 | doi = | url = | issn = }}</ref>

:cholest-5-ene-3β,7α-diol + NAD<sup>+</sup> <math>\rightleftharpoons</math> 7α-hydroxycholest-4-en-3-one + NADH + H<sup>+</sup>

Thus, the two [[substrate (biochemistry)|substrates]] of this enzyme are [[cholest-5-ene-3β,7α-diol]] and [[nicotinamide adenine dinucleotide|NAD<sup>+</sup>]], whereas its 3 [[product (chemistry)|products]] are [[7α-hydroxycholest-4-en-3-one]], [[nicotinamide adenine dinucleotide|NADH]], and [[hydrogen ion|H<sup>+</sup>]].

The [[List of enzymes|systematic name]] of this enzyme class is '''cholest-5-ene-3β,7α-diol:NAD<sup>+</sup> 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]].<ref name="pmid11067870">{{cite journal | vauthors = Schwarz M, Wright AC, Davis DL, Nazer H, Björkhem I, Russell DW | title = The bile acid synthetic gene 3β-hydroxy-Δ(5)-C(27)-steroid oxidoreductase is mutated in progressive intrahepatic cholestasis | journal = J. Clin. Invest. | volume = 106 | issue = 9 | pages = 1175–84 |date=November 2000 | pmid = 11067870 | pmc = 301421 | doi = 10.1172/JCI10902 | url = | issn = }}</ref><ref name="pmid19027726">{{cite journal | vauthors = 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 | title = The SDR (short-chain dehydrogenase/reductase and related enzymes) nomenclature initiative | journal = Chem. Biol. Interact. | volume = 178 | issue = 1–3 | pages = 94–8 |date=March 2009 | pmid = 19027726 | pmc = 2896744 | doi = 10.1016/j.cbi.2008.10.040 | url = | issn =}}</ref>

== Function ==

This enzyme belongs to the family of [[oxidoreductase]]s, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. This enzyme is involved in the initial stages of the synthesis of [[bile acid]]s 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.<ref name="entrez"/>

== 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.<ref name="entrez">{{cite web | title = Entrez Gene: HSD3B7 | url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=80270 | accessdate =}}</ref>

== See also ==

* [[3-beta-HSD]]

== References ==
{{reflist}}

{{NLM content}}
{{Alcohol oxidoreductases}}
{{Enzymes}}
{{Portal bar|Molecular and Cellular Biology|border=no}}

[[Category:EC 1.1.1]]
[[Category:NADH-dependent enzymes]]
[[Category:Enzymes of unknown structure]]


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