4DK1:
reference: Assembly and channel opening of outer membrane protein in tripartite drug efflux pumps of Gram-negative bacteria., Xu Y, Moeller A, Jun SY, Le M, Yoon BY, Kim JS, Lee K, Ha NC, J Biol Chem. 2012 Apr 6;287(15):11740-50. Epub 2012 Feb 3. PMID: 22308040

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