| 7-dehydrocholesterol reductase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.3.1.21 | ||||||||
| CAS no. | 9080-21-1 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
7-Dehydrocholesterol reductase, also known as DHCR7, is a protein that in humans is encoded by the DHCR7 gene.
The protein encoded by this gene is an enzyme catalyzing the reversible production of cholesterol from 7-dehydrocholesterol using nicotinamide adenine dinucleotide phosphate (NADPH) as its cofactor.
The DHCR7 gene encodes delta-7-sterol reductase (EC 1.3.1.21), the ultimate enzyme of mammalian sterol biosynthesis that converts 7-dehydrocholesterol (7-DHC) to cholesterol. This enzyme removes the C(7–8) double bond introduced by the sterol delta8-delta7 isomerases. In addition, its role in drug-induced malformations is known: inhibitors of the last step of cholesterol biosynthesis such as AY9944 and BM15766 severely impair brain development.
It displays a modest level of enzyme promiscuity, being able to catalyze analogous reactions with (substrate in forward direction) brassicasterol, 20S(OH)7DHC, 27(OH)DHC and 7-dehydrodesmosterol.
A deficiency is associated with Smith–Lemli–Opitz syndrome.
All house cats and dogs have higher-than-usual activity of this enzyme, causing an inability to synthesize vitamin D due to the lack of 7-dehydrocholesterol.
Click on genes, proteins and metabolites below to link to respective articles.
{{cite journal}}: CS1 maint: DOI inactive as of April 2026 (link)This article incorporates text from the United States National Library of Medicine, which is in the public domain.
