Purine nucleoside phosphorylase

UniProtKB accession:  Q8T9Z7

Grouped By:  Matching UniProtKB accession

UniProtKB description:  As part of the purine salvage pathway, catalyzes 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 (PubMed:11707439, PubMed:30602534). Preferentially acts on inosine and guanosine, and to a lesser extent on 2'-deoxyinosine and 2'-deoxyguanosine (PubMed:11707439). Also catalyzes the phosphorylation of S-methyl-5'-thioinosine (MTI) to hypoxanthine; MTI is produced by adenosine deaminase (ADA)-mediated breakdown of S-methyl-5'-thioadenosine (MTA), a major by-product of polyamine biosynthesis (By similarity). Generates hypoxanthine from both the purine salvage pathway and from polyamine metabolism which is required for nucleic acids synthesis (By similarity). Has no activity towards adenosine (PubMed:11707439).