PNP catalyzes the conversion of hypoxanthine and (deoxy)ribose to (deoxy)inosine

Stable Identifier
Reaction [transition]
Homo sapiens
hypoxanthine + (deoxy)ribose 1-phosphate <=> (deoxy)inosine + orthophosphate (NP)
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Cytosolic purine nucleoside phosphorylase (PNP) trimer catalyzes the reversible reaction of hypoxanthine with ribose 1-phosphate or deoxyribose 1-phosphate to form inosine or deoxyinosine and orthophosphate (Ealick et al. 1990; Wiginton et al. 1980). While PNP is active with either ribose 1-phosphate or deoxyribose 1-phosphate in vitro, levels of deoxyribose 1-phosphate are normally low in vivo, limiting the extent of this reaction. PNP deficiency in vivo is associated with defects in purine metabolism and leads to immunodeficiency (Williams et al. 1987).
Literature References
PubMed ID Title Journal Year
3029074 A human purine nucleoside phosphorylase deficiency caused by a single base change

Williams, SR, Gekeler, V, McIvor, RS, Martin, Jr, DW

J Biol Chem 1987
6771276 Characterization of purine nucleoside phosphorylase from human granulocytes and its metabolism of deoxyribonucleosides

Hutton, JJ, Wiginton, DA, Coleman, MS

J Biol Chem 1980
2104852 Three-dimensional structure of human erythrocytic purine nucleoside phosphorylase at 3.2 A resolution

Cook, WJ, Habash, J, Greenhough, TJ, Babu, YS, Carter, DC, Parks, Jr, RE, Rule, SA, Bugg, CE, Stoeckler, JD, Chen, SF, Ealick, SE, Helliwell, JR

J Biol Chem 1990
Event Information
Catalyst Activity

purine-nucleoside phosphorylase activity of PNP trimer [cytosol]

Orthologous Events
Cross References
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