2C1W:
reference: The structure of the endoribonuclease XendoU: From small nucleolar RNA processing to severe acute respiratory syndrome coronavirus replication., Renzi F, Caffarelli E, Laneve P, Bozzoni I, Brunori M, Vallone B, Proc Natl Acad Sci U S A. 2006 Aug 15;103(33):12365-70. Epub 2006 Aug 8. PMID: 16895992

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