3GMM image
Deposition Date 2009-03-14
Release Date 2009-11-10
Last Version Date 2024-10-30
Entry Detail
PDB ID:
3GMM
Keywords:
Title:
Structure of mouse CD1d in complex with C8Ph
Biological Source:
Source Organism:
Mus musculus (Taxon ID: 10090)
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.80 Å
R-Value Free:
0.21
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:T-cell surface glycoprotein CD1d1
Gene (Uniprot):Cd1d1
Chain IDs:A
Chain Length:287
Number of Molecules:1
Biological Source:Mus musculus
Polymer Type:polypeptide(L)
Molecule:Beta-2 microglobulin
Chain IDs:B
Chain Length:99
Number of Molecules:1
Biological Source:Mus musculus
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
ASN A ASN GLYCOSYLATION SITE
Primary Citation
Structural evaluation of potent NKT cell agonists: implications for design of novel stimulatory ligands.
J.Mol.Biol. 394 71 82 (2009)
PMID: 19732779 DOI: 10.1016/j.jmb.2009.08.061

Abstact

Natural killer T (NKT) cells are a subset of T cells that are activated by CD1d-glycolipid complexes through a semi-invariant alphabeta T cell receptor (NKT TCR). Upon activation, NKT cells secrete regulatory cytokines that are implicated in T helper cell responses. alpha-Galactosylceramide (alpha-GalCer) is a potent NKT cell agonist when presented by CD1d. Phenyl ring substitutions of the alpha-GalCer fatty acid moiety were recently found to be superior in eliciting regulatory cytokines. Crystal structures of four new mouse CD1d-lipid complexes (five structures), a new PBS-25 complex, and CD1d with an endogenous ligand, at 1.6-1.9 A resolution, reveal that the alpha-GalCer phenyl analogues impart minor structural differences to the A'-pocket, while the sphingosine and galactose moieties, important for NKT TCR recognition, remain virtually unchanged. The observed differences in cytokine-release profiles appear to be associated with increased stability of the CD1d-glycolipid complexes rather than increased affinity for the NKT TCR. Furthermore, comparison of mouse CD1d-glycolipid complexes in different crystallographic space groups reveals considerable conformational variation, particularly above the F'-pocket, the primary site of interaction with the NKT TCR. We propose that modifications of the sphingosine moiety or other substitutions that decrease alpha-GalCer flexibility would stabilize the F'-pocket. Such compounds might then increase CD1d affinity for the NKT TCR and further enhance the stimulatory and regulatory properties of alpha-GalCer derivatives.

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Primary Citation of related structures