Primary Citation of Related Structures:   1E4J, 1E4K
PubMed Abstract: 
The immune response depends on the binding of opsonized antigens to cellular Fc receptors and the subsequent initiation of various cellular effector functions of the immune system. Here we describe the crystal structures of a soluble Fc gamma receptor (sFc gammaRIII, CD16), an Fc fragment from human IgG1 (hFc1) and their complex ...
The immune response depends on the binding of opsonized antigens to cellular Fc receptors and the subsequent initiation of various cellular effector functions of the immune system. Here we describe the crystal structures of a soluble Fc gamma receptor (sFc gammaRIII, CD16), an Fc fragment from human IgG1 (hFc1) and their complex. In the 1:1 complex the receptor binds to the two halves of the Fc fragment in contact with residues of the C gamma2 domains and the hinge region. Upon complex formation the angle between the two sFc gammaRIII domains increases significantly and the Fc fragment opens asymmetrically. The high degree of amino acid conservation between sFc gammaRIII and other Fc receptors, and similarly between hFc1 and related immunoglobulins, suggest similar structures and modes of association. Thus the described structure is a model for immune complex recognition and helps to explain the vastly differing affinities of other Fc gammaR-IgG complexes and the Fc epsilonRI alpha-IgE complex.
Organizational Affiliation: 
Max-Planck-Institut für Biochemie, Martinsried, Germany. sonderma@biochem.mpg.de
Version 1.1: 2011-10-19 Changes: Data collection, Derived calculations, Non-polymer description, Other, Refinement description, Structure summary, Version format compliance
Version 2.0: 2020-07-29 Type: Remediation Reason: Carbohydrate remediation Changes: Atomic model, Data collection, Derived calculations, Structure summary