6JPT:
reference: Molecular and Structural Basis of the Proteasome alpha Subunit Assembly Mechanism Mediated by the Proteasome-Assembling Chaperone PAC3-PAC4 Heterodimer., Satoh T, Yagi-Utsumi M, Okamoto K, Kurimoto E, Tanaka K, Kato K, Int J Mol Sci. 2019 May 7;20(9). pii: ijms20092231. doi: 10.3390/ijms20092231. PMID: 31067643

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