Reaction: PNP catalyzes the conversion of guanine and (deoxy)ribose to (deoxy)guanosine

- in pathway: Purine salvage
Cytosolic purine nucleoside phosphorylase (PNP) trimer catalyzes the reversible reaction of guanine with ribose 1-phosphate or deoxyribose 1-phosphate to form guanosine or deoxyguanosine 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).
Reaction - small molecule participants:
Pi [cytosol]
Gua [cytosol]
Reactome.org reaction link: R-HSA-112034

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Reaction input - small molecules:
guanine
ChEBI:16235
Reaction output - small molecules:
hydrogenphosphate
ChEBI:43474
Reactome.org link: R-HSA-112034