2RPF:
reference: A non-canonical DNA structure enables homologous recombination in various genetic systems., Masuda T, Ito Y, Terada T, Shibata T, Mikawa T, J Biol Chem. 2009 Oct 30;284(44):30230-9. Epub 2009 Sep 3. PMID: 19729448

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