1YDP

1.9A crystal structure of HLA-G

Summary for 1YDP

• Entry DOI: 10.2210/pdb1ydp/pdb
• Descriptor: MHC class I antigen, Beta-2-microglobulin, histone 2a peptide, ... (6 entities in total)
• Functional Keywords: immune system
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 3
• Total formula weight: 45015.93

Authors

Clements, C.S.,Kjer-nielsen, L.,Kostenko, L.,Hoare, H.L.,Dunstone, M.A.,Moses, E.,Freed, K.,Brooks, A.G.,Rossjohn, J.,Mccluskey, J. (deposition date: 2004-12-25, release date: 2005-03-08, Last modification date: 2024-10-23)

Primary citation

Clements, C.S.,Kjer-Nielsen, L.,Kostenko, L.,Hoare, H.L.,Dunstone, M.A.,Moses, E.,Freed, K.,Brooks, A.G.,Rossjohn, J.,McCluskey, J.
Crystal structure of HLA-G: A nonclassical MHC class I molecule expressed at the fetal-maternal interface
PROC.NATL.ACAD.SCI.USA, 102:3360-3365, 2005

PubMed Abstract: HLA-G is a nonclassical major histocompatibility complex class I (MHC-I) molecule that is primarily expressed at the fetal-maternal interface, where it is thought to play a role in protecting the fetus from the maternal immune response. HLA-G binds a limited repertoire of peptides and interacts with the inhibitory leukocyte Ig-like receptors LIR-1 and LIR-2 and possibly with certain natural killer cell receptors. To gain further insights into HLA-G function, we determined the 1.9-A structure of a monomeric HLA-G complexed to a natural endogenous peptide ligand from histone H2A (RIIPRHLQL). An extensive network of contacts between the peptide and the antigen-binding cleft reveal a constrained mode of binding reminiscent of the nonclassical HLA-E molecule, thereby providing a structural basis for the limited peptide repertoire of HLA-G. The alpha3 domain of HLA-G, a candidate binding site for the LIR-1 and -2 inhibitory receptors, is structurally distinct from the alpha3 domains of classical MHC-I molecules, providing a rationale for the observed affinity differences for these ligands. The structural data suggest a head-to-tail mode of dimerization, mediated by an intermolecular disulfide bond, that is consistent with the observation of HLA-G dimers on the cell surface.

PubMed: 15718280
DOI: 10.1073/pnas.0409676102

Experimental method

X-RAY DIFFRACTION (1.9 Å)