| 1ECP: reference: The crystal structure of Escherichia coli purine nucleoside phosphorylase: a comparison with the human enzyme reveals a conserved topology., Mao C, Cook WJ, Zhou M, Koszalka GW, Krenitsky TA, Ealick SE, Structure 1997 Oct 15;5(10):1373-83. PMID: 9351810 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).