Crystal structure of human purine nucleoside phosphorylase at 2.3A resolution.
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.
de Azevedo
Walter Filgueira
WF
Departamento de Física, UNESP, São José do Rio Preto, SP, Brazil. walterfa@df.ibilce.unesp.br
Canduri
Fernanda
F
dos Santos
Denis Marangoni
DM
Silva
Rafael Guimarães
RG
de Oliveira
Jaim Simões
JS
de Carvalho
Luiz Pedro Sório
LP
Basso
Luiz Augusto
LA
Mendes
Maria Anita
MA
Palma
Mário Sérgio
MS
Santos
Diógenes Santiago
DS
D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010710:Phosphates / Q000737:chemistry; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D011683:Purine-Nucleoside Phosphorylase / Q000737:chemistry* / Q000378:metabolism
D004791:Enzyme Inhibitors; D008024:Ligands; D010710:Phosphates; D011683:Purine-Nucleoside Phosphorylase