purine-nucleoside phosphorylase activity GO:0004731 RHEA:19808 Reactome:REACT_1040 Reactome:REACT_84719 Reactome:REACT_105938 MetaCyc:PNP-RXN Reactome:REACT_29475 Reactome:REACT_90519 Reactome:REACT_81640 Reactome:REACT_82584 Reactome:REACT_83034 Reactome:REACT_82660 Reactome:REACT_104483 Reactome:REACT_104884 Reactome:REACT_101377 purine-nucleoside:phosphate ribosyltransferase activity Reactome:REACT_108845 Reactome:REACT_93793 Reactome:REACT_92186 Reactome:REACT_79445 EC:2.4.2.1 Reactome:REACT_99210 Reactome:REACT_80669 Reactome:REACT_77184 Reactome:REACT_32032 Reactome:REACT_85952 Reactome:REACT_32671 Reactome:REACT_77461 Reactome:REACT_83973 Reactome:REACT_84275 Reactome:REACT_30448 Reactome:REACT_82690 Reactome:REACT_104371 Reactome:REACT_93944 Reactome:REACT_94711 Reactome:REACT_92775 Reactome:REACT_758 Reactome:REACT_88195 Reactome:REACT_116164 Reactome:REACT_99029 Reactome:REACT_33350 Catalysis of the reaction: purine nucleoside + phosphate = purine + alpha-D-ribose 1-phosphate. Reactome:REACT_94051 purine ribonucleoside phosphorylase activity Reactome:REACT_85901 PUNPII Reactome:REACT_82113 Reactome:REACT_83049 Reactome:REACT_29370 purine deoxynucleoside phosphorylase activity Reactome:REACT_101795 purine nucleoside phosphorylase activity inosine-guanosine phosphorylase activity Reactome:REACT_41134 Reactome:REACT_97359 inosine phosphorylase activity Reactome:REACT_97633 Reactome:REACT_93331 Reactome:REACT_94783 Reactome:REACT_95751 molecular_function Reactome:REACT_95790 Reactome:REACT_77403 Reactome:REACT_31201 PUNPI Reactome:REACT_88807 Reactome:REACT_82860 Reactome:REACT_29320 purine deoxyribonucleoside phosphorylase activity PNPase activity Reactome:REACT_1518 Reactome:REACT_110314 Reactome:REACT_1636 Reactome:REACT_83680 Reactome:REACT_92835 Reactome:REACT_108434 Reactome:REACT_109206 Reactome:REACT_104353 Reactome:REACT_103023 Reactome:REACT_88493 Reactome:REACT_105402 transferase activity, transferring pentosyl groups