2D31

Crystal structure of disulfide-linked HLA-G dimer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.298 
  • R-Value Work: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Efficient Leukocyte Ig-like Receptor Signaling and Crystal Structure of Disulfide-linked HLA-G Dimer

Shiroishi, M.Kuroki, K.Ose, T.Rasubala, L.Shiratori, I.Arase, H.Tsumoto, K.Kumagai, I.Kohda, D.Maenaka, K.

(2006) J.Biol.Chem. 281: 10439-10447

  • DOI: 10.1074/jbc.M512305200

  • PubMed Abstract: 
  • HLA-G is a nonclassical major histocompatibility complex class I (MHCI) molecule, which is expressed in trophoblasts and confers immunological tolerance in the maternal-fetal interface by binding to leukocyte Ig-like receptors (LILRs, also called as ...

    HLA-G is a nonclassical major histocompatibility complex class I (MHCI) molecule, which is expressed in trophoblasts and confers immunological tolerance in the maternal-fetal interface by binding to leukocyte Ig-like receptors (LILRs, also called as LIR/ILT/CD85) and CD8. HLA-G is expressed in disulfide-linked dimer form both in solution and at the cell surface. Interestingly, MHCI dimer formations have been involved in pathogenesis and T cell activation. The structure and receptor binding characteristics of MHCI dimers have never been evaluated. Here we performed binding studies showing that the HLA-G dimer exhibited higher overall affinity to LILRB1/2 than the monomer by significant avidity effects. Furthermore, the cell reporter assay demonstrated that the dimer formation remarkably enhanced the LILRB1-mediated signaling at the cellular level. We further determined the crystal structure of the wild-type dimer of HLA-G with the intermolecular Cys(42)-Cys(42) disulfide bond. This dimer structure showed the oblique configuration to expose two LILR/CD8-binding sites upward from the membrane easily accessible for receptors, providing plausible 1:2 (HLA-G dimer:receptors) complex models. These results indicated that the HLA-G dimer conferred increased avidity in a proper structural orientation to induce efficient LILR signaling, resulting in the dominant immunosuppressive effects. Moreover, structural and functional implications for other MHCI dimers observed in activated T cells and the pathogenic allele, HLA-B27, are discussed.


    Organizational Affiliation

    Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA class I histocompatibility antigen, alpha chain G
A, D
276Homo sapiensMutation(s): 0 
Gene Names: HLA-G (HLA-6.0, HLAG)
Find proteins for P17693 (Homo sapiens)
Go to Gene View: HLA-G
Go to UniProtKB:  P17693
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Beta-2-microglobulin
B, E
100Homo sapiensMutation(s): 0 
Gene Names: B2M
Find proteins for P61769 (Homo sapiens)
Go to Gene View: B2M
Go to UniProtKB:  P61769
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
9-mer peptide from Histone H2A
C, F
9Homo sapiensMutation(s): 0 
Gene Names: H2AFX (H2AX)
Find proteins for P16104 (Homo sapiens)
Go to Gene View: H2AFX
Go to UniProtKB:  P16104
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.2 Å
  • R-Value Free: 0.298 
  • R-Value Work: 0.235 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 94.641α = 90.00
b = 127.807β = 90.00
c = 72.580γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
MOLREPphasing
HKL-2000data reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-03-14
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance