3G40:
reference: X-ray Structure of the C-Terminal Domain of a Prokaryotic Cation-Chloride Cotransporter., Warmuth S, Zimmermann I, Dutzler R, Structure. 2009 Apr 15;17(4):538-46. PMID: 19368887

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