1XPF:
reference: Polymorphism of Bulged-out Residues in HIV-1 RNA DIS Kissing Complex and Structure Comparison with Solution Studies., Ennifar E, Dumas P, J Mol Biol. 2006 Feb 24;356(3):771-82. Epub 2005 Dec 21. PMID: 16403527

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