1RXU:
reference: Crystal structures of Escherichia coli uridine phosphorylase in two native and three complexed forms reveal basis of substrate specificity, induced conformational changes and influence of potassium., Caradoc-Davies TT, Cutfield SM, Lamont IL, Cutfield JF, J Mol Biol 2004 Mar 19;337(2):337-54. PMID: 15003451

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