2H2R

Crystal structure of the human CD23 Lectin domain, apo form

Summary for 2H2R

• Entry DOI: 10.2210/pdb2h2r/pdb
• Related: 1HLI 1HLJ 1KJE 1T8C 1T8D 2H2T
• Descriptor: Low affinity immunoglobulin epsilon Fc receptor (Lymphocyte IgE receptor) (Fc-epsilon-RII)(Immunoglobulin E-binding factor) (CD23 antigen) (2 entities in total)
• Functional Keywords: c-type lectin, apo form, lectin domain, low affinity ige receptor, immune system
• Biological source: Homo sapiens (human)
• Cellular location: Cell membrane; Single-pass type II membrane protein: P06734
• Total number of polymer chains: 2
• Total formula weight: 39031.43

Authors

Wurzburg, B.A. (deposition date: 2006-05-19, release date: 2006-06-20, Last modification date: 2023-08-30)

Primary citation

Wurzburg, B.A.,Tarchevskaya, S.S.,Jardetzky, T.S.
Structural Changes in the Lectin Domain of CD23, the Low-Affinity IgE Receptor, upon Calcium Binding.
Structure, 14:1049-1058, 2006

PubMed Abstract: CD23, the low-affinity receptor for IgE (Fc epsilonRII), regulates IgE synthesis and also mediates IgE-dependent antigen transport and processing. CD23 is a unique Fc receptor belonging to the C-type lectin-like domain superfamily and binds IgE in an unusual, non-lectin-like manner, requiring calcium but not carbohydrate. We have solved the high-resolution crystal structures of the human CD23 lectin domain in the presence and absence of Ca2+. The crystal structures differ significantly from a previously determined NMR structure and show that calcium binding occurs at the principal binding site, but not at an auxiliary site that appears to be absent in human CD23. Conformational differences between the apo and Ca2+ bound structures suggest how IgE-Fc binding can be both calcium-dependent and carbohydrate-independent.

PubMed: 16765898
DOI: 10.1016/j.str.2006.03.017

Experimental method

X-RAY DIFFRACTION (1.5 Å)