3IPM:
reference: Interactions of PAN's C-termini with archaeal 20S proteasome and implications for the eukaryotic proteasome-ATPase interactions., Yu Y, Smith DM, Kim HM, Rodriguez V, Goldberg AL, Cheng Y, EMBO J. 2009 Dec 17. PMID: 20019667

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