1R9W:
reference: The DNA-binding domain of human papillomavirus type 18 E1. Crystal structure, dimerization, and DNA binding., Auster AS, Joshua-Tor L, J Biol Chem 2004 Jan 30;279(5):3733-42. Epub 2003 Oct 30. PMID: 14593106

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