The crystal structure of an avian IgY-Fc fragment reveals conservation with both mammalian IgG and IgE.
Avian IgY is closely related to an ancestor of both mammalian IgG and IgE and thus provides insights into the evolution of antibody structure and function. A recombinant fragment of IgY-Fc consisting of a dimer of the Cupsilon3 and Cupsilon4 domains, Fcupsilon3-4, was expressed and crystallized and its X-ray structure determined to 1.75 A resolution. Fcupsilon3-4 is the only nonmammalian Fc fragment structure determined to date and provides the first structural evidence for an ancient origin of antibody architecture. The Fcupsilon3-4 structure reveals features common to both IgE-Fc and IgG-Fc, and the implications for IgY binding to its receptor are discussed.
Taylor
Alexander I
AI
Randall Division of Cell and Molecular Biophysics, King's College London, and MRC-Asthma UK Centre in Allergic Mechanisms of Asthma, New Hunt's House, Guy's Campus, London SE1 1UL, United Kingdom.
Fabiane
Stella M
SM
Sutton
Brian J
BJ
Calvert
Rosaleen A
RA
D000818:Animals; D045744:Cell Line, Tumor; D002645:Chickens / Q000276:immunology*; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007073:Immunoglobulin E / Q000737:chemistry*; D007141:Immunoglobulin Fc Fragments / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry*; D007136:Immunoglobulins / Q000737:chemistry*; D008322:Mammals / Q000276:immunology*; D051379:Mice; D017433:Protein Structure, Secondary
C016512:IgY; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007136:Immunoglobulins; D007073:Immunoglobulin E