4RNA:
reference: Inhibitor Recognition Specificity of MERS-CoV Papain-like Protease May Differ from That of SARS-CoV., Lee H, Lei H, Santarsiero BD, Gatuz JL, Cao S, Rice AJ, Patel K, Szypulinski MZ, Ojeda I, Ghosh AK, Johnson ME, ACS Chem Biol. 2015 Mar 16. PMID: 25746232

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