4I1A:
reference: Conformational change-induced repeat domain expansion regulates rap phosphatase quorum-sensing signal receptors., Parashar V, Jeffrey PD, Neiditch MB, PLoS Biol. 2013 Mar;11(3):e1001512. doi: 10.1371/journal.pbio.1001512. Epub 2013 , Mar 19. PMID: 23526881

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