SRD5A3 : steroid 5 alpha-reductase 3
Description
The SRD5A3 (steroid 5 alpha-reductase 3) is a protein-coding gene located on chromosome 4.
The SRD5A3 gene provides instructions for making an enzyme called steroid 5-alpha reductase 3. This enzyme performs a chemical reaction that converts a compound called polyprenol into another compound called dolichol. Subsequently, another enzyme converts dolichol to dolichol phosphate. The production of dolichol phosphate is critical for a process called glycosylation, by which small chains of sugar molecules (oligosaccharides) are attached to proteins. Glycosylation changes proteins in ways that are important for their functions. Dolichol phosphate is integral for the formation of the sugar chains that are attached to proteins during glycosylation. Individual sugars are added to dolichol phosphate to build the oligosaccharide chain. Once the chain is formed, it is transferred from dolichol phosphate to a specific site on the protein that needs to be glycosylated.
The SRD5A3 gene encodes an enzyme called steroid 5-alpha reductase 3, which plays a key role in early steps of protein N-linked glycosylation by converting polyprenol into dolichol. Dolichols are required for the synthesis of dolichol-linked monosaccharides and the oligosaccharide precursor used for N-glycosylation. This enzyme acts as a polyprenol reductase, promoting the reduction of the alpha-isoprene unit of polyprenols into dolichols in a NADP-dependent mechanism. Additionally, SRD5A3 can convert testosterone (T) into 5-alpha-dihydrotestosterone (DHT).
SRD5A3 is also known as CDG1P, CDG1Q, KRIZI, S5AR, S5AR 3, SRD5A2L, SRD5A2L1.
Associated Diseases
- Kahrizi syndrome
- SRD5A3-CDG
- Congenital disorder of glycosylation, type IQ
- SRD5A3-congenital disorder of glycosylation
