6GDS:
reference: Holliday Junctions Formed from Human Telomeric DNA., Haider S, Li P, Khiali S, Munnur D, Ramanathan A, Parkinson GN, J Am Chem Soc. 2018 Oct 30. doi: 10.1021/jacs.8b08699. PMID: 30376323

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