| 1K9S: reference: Open and closed conformation of the E. coli purine nucleoside phosphorylase active center and implications for the catalytic mechanism., Koellner G, Bzowska A, Wielgus-Kutrowska B, Luic M, Steiner T, Saenger W, Stepinski J, J Mol Biol 2002 Jan 18;315(3):351-71. PMID: 11786017 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).