4BUJ:
reference: The yeast ski complex: crystal structure and RNA channeling to the exosome complex., Halbach F, Reichelt P, Rode M, Conti E, Cell. 2013 Aug 15;154(4):814-26. doi: 10.1016/j.cell.2013.07.017. PMID: 23953113

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