1KSE:
reference: On the effect of covalently appended quinolones on termini of DNA duplexes., Tuma J, Connors WH, Stitelman DH, Richert C, J Am Chem Soc 2002 Apr 24;124(16):4236-46. PMID: 11960452

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