3TEX:
reference: Domain flexibility modulates the heterogeneous assembly mechanism of anthrax toxin protective antigen., Feld GK, Kintzer AF, Tang II, Thoren KL, Krantz BA, J Mol Biol. 2012 Jan 6;415(1):159-74. Epub 2011 Oct 31. PMID: 22063095

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