2HQ5:
reference: Multidrug-binding transcription factor QacR binds the bivalent aromatic diamidines DB75 and DB359 in multiple positions., Brooks BE, Piro KM, Brennan RG, J Am Chem Soc. 2007 Jul 4;129(26):8389-95. Epub 2007 Jun 13. PMID: 17567017

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