2MRZ:
reference: Centromeric Alpha-Satellite DNA Adopts Dimeric i-Motif Structures Capped by AT Hoogsteen Base Pairs., Garavis M, Escaja N, Gabelica V, Villasante A, Gonzalez C, Chemistry. 2015 May 27. doi: 10.1002/chem.201500448. PMID: 26013031

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