3D0X:
reference: Crystal structure of the lysine riboswitch regulatory mRNA element., Garst AD, Heroux A, Rambo RP, Batey RT, J Biol Chem. 2008 Aug 15;283(33):22347-51. Epub 2008 Jul 1. PMID: 18593706

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