| 3K0O: reference: Hidden alternative structures of proline isomerase essential for catalysis., Fraser JS, Clarkson MW, Degnan SC, Erion R, Kern D, Alber T, Nature. 2009 Dec 3;462(7273):669-73. PMID: 19956261 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).