4KSR:
reference: Hexamers of the Type II Secretion ATPase GspE from Vibrio cholerae with Increased ATPase Activity., Lu C, Turley S, Marionni ST, Park YJ, Lee KK, Patrick M, Shah R, Sandkvist M, Bush MF, Hol WG, Structure. 2013 Aug 13. pii: S0969-2126(13)00256-6. doi:, 10.1016/j.str.2013.06.027. PMID: 23954505

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