3ZDE:
reference: The structure of Escherichia coli ExoIX--implications for DNA binding and catalysis in flap endonucleases., Anstey-Gilbert CS, Hemsworth GR, Flemming CS, Hodskinson MR, Zhang J, Sedelnikova SE, Stillman TJ, Sayers JR, Artymiuk PJ, Nucleic Acids Res. 2013 Jul 2. PMID: 23821668

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