2IDN:
reference: A new modified thrombin binding aptamer containing a 5'-5' inversion of polarity site., Martino L, Virno A, Randazzo A, Virgilio A, Esposito V, Giancola C, Bucci M, Cirino G, Mayol L, Nucleic Acids Res. 2006;34(22):6653-62. Epub 2006 Dec 1. PMID: 17145716

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