6BZ4:
reference: Global conformational changes in IgG-Fc upon mutation of the FcRn binding site are not associated with altered antibody-dependent effector functions., Burvenich IJG, Farrugia W, Liu Z, Makris D, King D, Gloria B, Perani A, Allan LC, Scott AM, Ramsland PA, Biochem J. 2018 May 24. pii: BCJ20180139. doi: 10.1042/BCJ20180139. PMID: 29794155

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