5IY4:
reference: Crystal structure of human PCNA in complex with the PIP box of DVC1., Wang Y, Xu M, Jiang T, Biochem Biophys Res Commun. 2016 May 27;474(2):264-70. doi:, 10.1016/j.bbrc.2016.04.053. Epub 2016 Apr 13. PMID: 27084448

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