3Q7K:
reference: pH-dependent gating in a FocA formate channel., Lu W, Du J, Wacker T, Gerbig-Smentek E, Andrade SL, Einsle O, Science. 2011 Apr 15;332(6027):352-4. PMID: 21493860

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