4KU1:
reference: Immunoglobulin G1 Fc Domain Motions: Implications for Fc Engineering., Frank M, Walker RC, Lanzilotta WN, Prestegard JH, Barb AW, J Mol Biol. 2014 Feb 9. pii: S0022-2836(14)00069-2. doi:, 10.1016/j.jmb.2014.01.011. PMID: 24522230

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