3BNS:
reference: The bacterial and mitochondrial ribosomal A-site molecular switches possess different conformational substates., Kondo J, Westhof E, Nucleic Acids Res. 2008 May;36(8):2654-66. Epub 2008 Mar 16. PMID: 18346970

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