3OGC:
reference: Mechanism for selectivity-inactivation coupling in KcsA potassium channels., Cheng WW, McCoy JG, Thompson AN, Nichols CG, Nimigean CM, Proc Natl Acad Sci U S A. 2011 Mar 29;108(13):5272-7. Epub 2011 Mar 14. PMID: 21402935

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