4BFG:
reference: Structures of CD200/CD200 Receptor Family and Implications for Topology, Regulation, and Evolution., Hatherley D, Lea SM, Johnson S, Barclay AN, Structure. 2013 Apr 17. pii: S0969-2126(13)00090-7. doi:, 10.1016/j.str.2013.03.008. PMID: 23602662

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