PDBsum entry 4ki1

Immune system

PDB id: 4ki1

Contents

Protein chains

208 a.a.

132 a.a.

Ligands

NAG-NAG-BMA-MAN-MAN ×4

Waters ×3

PDB id:

4ki1

Name:

Immune system

Title:

Primitive triclinic crystal form of the human ige-fc(epsilon)3-4 bound to its b cell receptor dercd23

Structure:

Ig epsilon chain c region. Chain: a, b, c, d. Fragment: human ige-fc(epsilon)3-4, unp residues 209-428. Engineered: yes. Mutation: yes. Low affinity immunoglobulin epsilon fc receptor. Chain: e, f, g, h. Fragment: human dercd23, unp residues 156-298. Synonym: blast-2, c-type lectin domain family 4 member j, fc-epsilon-

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: ighe. Expressed in: homo sapiens. Expression_system_taxid: 9606. Expression_system_cell_line: hek293. Gene: fcer2, cd23a, clec4j, fce2, igebf. Expressed in: escherichia coli.

Resolution:

3.20Å R-factor: 0.234 R-free: 0.266

Authors:

B.Dhaliwal,M.O.Y.Pang,B.J.Sutton,A.J.Beavil

Key ref:

B.Dhaliwal et al. (2014). A range of Cℇ3-Cℇ4 interdomain angles in IgE Fc accommodate binding to its receptor CD23. Acta Crystallogr F Struct Biol Commun, 70, 305-309. PubMed id: 24598915 DOI: 10.1107/S2053230X14003355

Date:

01-May-13 Release date: 05-Mar-14

Protein chains

P01854  (IGHE_HUMAN) -  Immunoglobulin heavy constant epsilon from Homo sapiens

Seq: 546 a.a.

Struc: 208 a.a.*

Protein chains

P06734  (FCER2_HUMAN) -  Low affinity immunoglobulin epsilon Fc receptor from Homo sapiens

Seq: 321 a.a.

Struc: 132 a.a.

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

DOI no: 10.1107/S2053230X14003355

Acta Crystallogr F Struct Biol Commun 70:305-309 (2014)

PubMed id: 24598915

A range of Cℇ3-Cℇ4 interdomain angles in IgE Fc accommodate binding to its receptor CD23.

B.Dhaliwal, M.O.Pang, D.Yuan, A.J.Beavil, B.J.Sutton.

ABSTRACT

The antibody IgE plays a central role in allergic disease, functioning principally through two cell-surface receptors: FcℇRI and CD23. FcℇRI on mast cells and basophils mediates the immediate hypersensitivity response, whilst the interaction of IgE with CD23 on B cells regulates IgE production. Crystal structures of the lectin-like `head' domain of CD23 alone and bound to a subfragment of IgE consisting of the dimer of Cℇ3 and Cℇ4 domains (Fcℇ3-4) have recently been determined, revealing flexibility in the IgE-binding site of CD23. Here, a new crystal form of the CD23-Fcℇ3-4 complex with different molecular-packing constraints is reported, which together with the earlier results demonstrates that conformational variability at the interface extends additionally to the IgE Fc and the quaternary structure of its domains.