4F4L:
reference: Structure of a bacterial voltage-gated sodium channel pore reveals mechanisms of opening and closing., McCusker EC, Bagneris C, Naylor CE, Cole AR, D'Avanzo N, Nichols CG, Wallace BA, Nat Commun. 2012 Oct 2;3:1102. doi: 10.1038/ncomms2077. PMID: 23033078

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