1BCE:
reference: Comparison of the solution structures of intramolecular DNA triple helices containing adjacent and non-adjacent CG.C+ triplets., Asensio JL, Brown T, Lane AN, Nucleic Acids Res 1998 Aug 15;26(16):3677-86. PMID: 9685482

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