3MP2:
reference: Papain-Like Protease 1 from Transmissible Gastroenteritis Virus: Crystal Structure and Enzymatic Activity toward Viral and Cellular Substrates., Wojdyla JA, Manolaridis I, van Kasteren PB, Kikkert M, Snijder EJ, Gorbalenya AE, Tucker PA, J Virol. 2010 Oct;84(19):10063-73. Epub 2010 Jul 28. PMID: 20668092

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