3E8B:
reference: Structural analysis of ion selectivity in the NaK channel., Alam A, Jiang Y, Nat Struct Mol Biol. 2009 Jan;16(1):35-41. Epub 2008 Dec 21. PMID: 19098915

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