1PR0:
reference: Structural basis for substrate specificity of Escherichia coli purine nucleoside phosphorylase., Bennett EM, Li C, Allan PW, Parker WB, Ealick SE, J Biol Chem 2003 Nov 21;278(47):47110-8. Epub 2003 Aug 21. PMID: 12937174

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).