Enables purine-nucleoside phosphorylase activity. Involved in purine nucleoside metabolic process. Located in cytoplasm; extracellular region; and nucleus. Human ortholog(s) of this gene implicated in purine nucleoside phosphorylase deficiency and purine-pyrimidine metabolic disorder. Orthologous to human PNP (purine nucleoside phosphorylase). [provided by Alliance of Genome Resources, Apr 2022]