6DTM:
reference: Structures of the Ligand-Binding Domain of Helicobacter pylori Chemoreceptor TlpA., Sweeney EG, Perkins A, Kallio K, Remington SJ, Guillemin K, Protein Sci. 2018 Aug 31. doi: 10.1002/pro.3503. PMID: 30171638

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