5KHY:
reference: Genetically Directed Production of Recombinant, Isosteric and Nonhydrolysable Ubiquitin Conjugates., Stanley M, Virdee S, Chembiochem. 2016 Aug 3;17(15):1472-80. doi: 10.1002/cbic.201600138. Epub 2016, Jun 27. PMID: 27197715

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