CRYSTAL STRUCTURE OF HUMAN PNP AT 2.3A RESOLUTION
[PNPH_HUMAN] Defects in PNP are the cause of purine nucleoside phosphorylase deficiency (PNPD) [MIM:613179]. It leads to a severe T-cell immunodeficiency with neurologic disorder in children.  
[PNPH_HUMAN] 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.
Publication Abstract from PubMed
Purine nucleoside phosphorylase (PNP) catalyzes the phosphorolysis of the N-ribosidic bonds of purine nucleosides and deoxynucleosides. In human, PNP is the only route for degradation of deoxyguanosine and genetic deficiency of this enzyme leads to profound T-cell mediated immunosuppression. PNP is therefore a target for inhibitor development aiming at T-cell immune response modulation and its low resolution structure has been used for drug design. Here we report the structure of human PNP solved to 2.3A resolution using synchrotron radiation and cryocrystallographic techniques. This structure allowed a more precise analysis of the active site, generating a more reliable model for substrate binding. The higher resolution data allowed the identification of water molecules in the active site, which suggests binding partners for potential ligands. Furthermore, the present structure may be used in the new structure-based design of PNP inhibitors.
Crystal structure of human purine nucleoside phosphorylase at 2.3A resolution.,de Azevedo WF Jr, Canduri F, dos Santos DM, Silva RG, de Oliveira JS, de Carvalho LP, Basso LA, Mendes MA, Palma MS, Santos DS Biochem Biophys Res Commun. 2003 Aug 29;308(3):545-52. PMID:12914785
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.