4GT7:
reference: An engineered disulfide bond reversibly traps the IgE-Fc3-4 in a closed, nonreceptor binding conformation., Wurzburg BA, Kim B, Tarchevskaya SS, Eggel A, Vogel M, Jardetzky TS, J Biol Chem. 2012 Oct 19;287(43):36251-7. doi: 10.1074/jbc.M112.407502. Epub 2012, Sep 4. PMID: 22948141

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