2E9R:
reference: Sequential structures provide insights into the fidelity of RNA replication., Ferrer-Orta C, Arias A, Perez-Luque R, Escarmis C, Domingo E, Verdaguer N, Proc Natl Acad Sci U S A. 2007 May 29;104(22):9463-8. Epub 2007 May 21. PMID: 17517631

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