2GOT:
reference: The structure of a d(gcGAACgc) duplex containing two consecutive bulged A residues in both strands suggests a molecular switch., Kondo J, Sunami T, Takenaka A, Acta Crystallogr D Biol Crystallogr. 2007 Jun;63(Pt 6):673-81. Epub 2007, May 15. PMID: 17505105

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