Defective PNP does not convert (deoxy)guanosine to guanine and (deoxy)ribose

Stable Identifier
R-HSA-9735789
Type
Reaction [transition]
Species
Homo sapiens
Compartment
ReviewStatus
5/5
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Normally in humans, PNP (purine nucleotide phosphorylase) catalyzes the reaction of (deoxy)guanosine with phosphate to yield guanine and (deoxy)ribose. In the absence of PNP activity, however, guanosine and deoxyguanosine accumulate and the formation of deoxy-GTP from the latter is thought to disrupt DNA replication especially in lymphoid cells, leading to severe immunodeficiency. Here, we have annotated the failure of this reaction due to three missense mutant alleles of PNP, identified in patients with severe immunodeficiency and shown to encode catalytically inactive forms of PNP protein (Aust et al. 1992; 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
1384322 Molecular analysis of mutations in a patient with purine nucleoside phosphorylase deficiency

Barrett, MJ, Andrews, LG, Markert, ML, Norby-Slycord, CJ, Aust, MR

Am J Hum Genet 1992
Participants
Participates
Catalyst Activity

purine-nucleoside phosphorylase activity of PNP trimer mutants [cytosol]

Normal reaction
Functional status

Loss of function of PNP trimer mutants [cytosol]

Status
Disease
Name Identifier Synonyms
purine nucleoside phosphorylase deficiency DOID:5813 deficiency of inosine phosphorylase, Purine nucleoside phosphorylase deficiency, PNP deficiency, Purine-Nucleoside Phosphorylase deficiency
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