5V7M:
reference: Crystal structures of PCNA mutant proteins defective in gene silencing suggest a novel interaction site on the front face of the PCNA ring., Kondratick CM, Litman JM, Shaffer KV, Washington MT, Dieckman LM, PLoS One. 2018 Mar 2;13(3):e0193333. doi: 10.1371/journal.pone.0193333., eCollection 2018. PMID: 29499038

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