Catalyzes the hydrolysis of the N-glycosidic bond of all of the commonly occurring purine and pyrimidine nucleosides into ribose and the associated base, but has a preference for inosine and uridine as substrates. Likely functions in purine salvage from the host, a fundamental pathway since protozoan parasites such as L.major are incapable of de novo purine biosynthesis. H2O + inosine = D-ribose + hypoxanthine H2O + uridine = D-ribose + uracil Is potently inhibited by immucillin A and immucillin ACAP, which are transition state inhibitors. kcat is 119 sec(-1) with inosine as substrate. kcat is 32 sec(-1) with uridine as substrate. kcat is 0.6 sec(-1) with guanosine as substrate. kcat is 0.6 sec(-1) with adenosine as substrate. kcat is 0.4 sec(-1) with cytidine as substrate. Purine metabolism; purine nucleoside salvage. Homotetramer. Belongs to the IUNH family.