MSMO1
Domain
The histidine box domains may contain the active site and/or be involved in metal ion binding.
Function
Catalyzes the three-step monooxygenation required for the demethylation of 4,4-dimethyl and 4alpha-methylsterols, which can be subsequently metabolized to cholesterol (PubMed:21285510, PubMed:23583456, PubMed:26114596, PubMed:28673550). Also involved in drug metabolism, as it can metabolize eldecalcitol (ED-71 or 1alpha,25-dihydroxy-2beta-(3-hydroxypropoxy)-cholecalciferol), a second-generation vitamin D analog, into 1alpha,2beta,25-trihydroxy vitamin D3; this reaction occurs via enzymatic hydroxylation and spontaneous O-dehydroxypropylation (PubMed:26038696).
Involvement in disease
Microcephaly, congenital cataract, and psoriasiform dermatitis
MCCPD
An autosomal recessive inborn error of cholesterol metabolism characterized by accumulation of a large amount of methylsterols, particularly dimethylsterols, in affected individuals. Patients manifest psoriasiform dermatitis, arthralgias, congenital cataracts, microcephaly, and developmental delay.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Steroid biosynthesis; zymosterol biosynthesis; zymosterol from lanosterol: step 3/6.
Steroid biosynthesis; cholesterol biosynthesis.
Sequence Similarities
Belongs to the sterol desaturase family.
Cellular localization
- Endoplasmic reticulum membrane
- Multi-pass membrane protein
Alternative names
DESP4, ERG25, SC4MOL, MSMO1, Methylsterol monooxygenase 1, C-4 methylsterol oxidase, Sterol-C4-methyl oxidase