3JTL:
reference: Structural models for interactions between the 20S proteasome and its PAN/19S activators., Stadtmueller BM, Ferrell K, Whitby FG, Heroux A, Robinson H, Myszka DG, Hill CP, J Biol Chem. 2009 Nov 4. PMID: 19889631

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