2LXQ:
reference: RecA-Binding pilE G4 Sequence Essential for Pilin Antigenic Variation Forms Monomeric and 5' End-Stacked Dimeric Parallel G-Quadruplexes., Kuryavyi V, Cahoon LA, Seifert HS, Patel DJ, Structure. 2012 Oct 16. pii: S0969-2126(12)00347-4. doi:, 10.1016/j.str.2012.09.013. PMID: 23085077

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