8Z0T image
Deposition Date 2024-04-10
Release Date 2024-07-10
Last Version Date 2025-07-02
Entry Detail
PDB ID:
8Z0T
Title:
Structure of the human ige-fc bound to its high affinity receptor fc(epsilon)
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
3.58 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:High affinity immunoglobulin epsilon receptor subunit alpha
Gene (Uniprot):FCER1A
Chain IDs:A
Chain Length:257
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Isoform 1 of Immunoglobulin heavy constant epsilon
Gene (Uniprot):IGHE
Chain IDs:B (auth: D), C (auth: E)
Chain Length:353
Number of Molecules:2
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Structural insights into the high-affinity IgE receptor Fc epsilon RI complex.
Nature 633 952 959 (2024)
PMID: 39169187 DOI: 10.1038/s41586-024-07864-5

Abstact

Immunoglobulin E (IgE) plays a pivotal role in allergic responses1,2. The high-affinity IgE receptor, FcεRI, found on mast cells and basophils, is central to the effector functions of IgE. FcεRI is a tetrameric complex, comprising FcεRIα, FcεRIβ and a homodimer of FcRγ (originally known as FcεRIγ), with FcεRIα recognizing the Fc region of IgE (Fcε) and FcεRIβ-FcRγ facilitating signal transduction3. Additionally, FcRγ is a crucial component of other immunoglobulin receptors, including those for IgG (FcγRI and FcγRIIIA) and IgA (FcαRI)4-8. However, the molecular basis of FcεRI assembly and the structure of FcRγ have remained elusive. Here we elucidate the cryogenic electron microscopy structure of the Fcε-FcεRI complex. FcεRIα has an essential role in the receptor's assembly, interacting with FcεRIβ and both FcRγ subunits. FcεRIβ is structured as a compact four-helix bundle, similar to the B cell antigen CD20. The FcRγ dimer exhibits an asymmetric architecture, and coils with the transmembrane region of FcεRIα to form a three-helix bundle. A cholesterol-like molecule enhances the interaction between FcεRIβ and the FcεRIα-FcRγ complex. Our mutagenesis analyses further indicate similarities between the interaction of FcRγ with FcεRIα and FcγRIIIA, but differences in that with FcαRI. These findings deepen our understanding of the signalling mechanisms of FcεRI and offer insights into the functionality of other immune receptors dependent on FcRγ.

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Primary Citation of related structures