Purine nucleoside phosphorylase
Short name=PNP
EC=2.4.2.1
Alternative name(s):
Inosine phosphorylase
Inosine-guanosine phosphorylase
Gene names
Name: PNP
Synonyms: NP
- Function
- The purine nucleoside phosphorylases catalyze the phosphorolytic breakdown of the N-glycosidic bond in the beta-(deoxy)ribonucleoside molecules, with the formation of the corresponding free purine bases and pentose-1-phosphate. Ref.13
- Catalytic activity
- Purine nucleoside + phosphate = purine + alpha-D-ribose 1-phosphate.
- Pathway
- Purine metabolism; purine nucleoside salvage.
- Subunit structure
- Homotrimer.
- Subcellular location
- Cytoplasm › cytoskeleton By similarity. Cytoplasm Ref.12.
- Tissue specificity
- Expressed in red blood cells; overexpressed in red blood cells (cytoplasm) of patients with hereditary non-spherocytic hemolytic anemia of unknown etiology.
- Involvement in disease
- Purine nucleoside phosphorylase deficiency (PNPD) [MIM:613179]: A disorder that interrupts both the catabolism of inosine into hypoxanthine and guanosine into guanine, and leads to the accumulation of guanosine, inosine, and their deoxified by-products. The main clinical presentation is recurrent infections due to severe T-cell immunodeficiency. Some patients also have neurologic impairment.
Note: The disease is caused by mutations affecting the gene represented in this entry.
