4J2Q:
reference: Crystal structure of pre-activated arrestin p44., Kim YJ, Hofmann KP, Ernst OP, Scheerer P, Choe HW, Sommer ME, Nature. 2013 Apr 21. doi: 10.1038/nature12133. PMID: 23604253

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