5GKC:
reference: Crystal structure of endonuclease G in complex with DNA reveals how it nonspecifically degrades DNA as a homodimer., Lin JL, Wu CC, Yang WZ, Yuan HS, Nucleic Acids Res. 2016 Dec 1;44(21):10480-10490. Epub 2016 Oct 13. PMID: 27738134

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