2XK5:
reference: Engineered diubiquitin synthesis reveals Lys29-isopeptide specificity of an OTU deubiquitinase., Virdee S, Ye Y, Nguyen DP, Komander D, Chin JW, Nat Chem Biol. 2010 Oct;6(10):750-7. Epub 2010 Aug 29. PMID: 20802491

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