6H1K:
reference: Major G-Quadruplex Form of HIV-1 LTR Reveals a (3 + 1) Folding Topology Containing a Stem-Loop., Butovskaya E, Heddi B, Bakalar B, Richter SN, Phan AT, J Am Chem Soc. 2018 Oct 9. doi: 10.1021/jacs.8b05332. PMID: 30299955

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