3INO:
reference: Domain 4 of the anthrax protective antigen maintains structure and binding to the host receptor CMG2 at low pH., Williams AS, Lovell S, Anbanandam A, El-Chami R, Bann JG, Protein Sci. 2009 Nov;18(11):2277-86. PMID: 19722284

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