2OJ0:
reference: Cation-dependent cleavage of the duplex form of the subtype-B HIV-1 RNA dimerization initiation site., Ennifar E, Walter P, Dumas P, Nucleic Acids Res. 2010 Sep 1;38(17):5807-16. Epub 2010 May 11. PMID: 20460458

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