1CQL:
reference: Structure of the phylogenetically most conserved domain of SRP RNA., Schmitz U, Behrens S, Freymann DM, Keenan RJ, Lukavsky P, Walter P, James TL, RNA 1999 Nov;5(11):1419-29. PMID: 10580470

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