4UDU: Crystal Structure Of Staphylococcal Enterotoxin E In Complex With A T Cell Receptor

T cells are crucial players in cell-mediated immunity. The specificity of their receptor, the T cell receptor (TCR), is central for the immune system to distinguish foreign from host antigens. Superantigens are bacterial toxins capable of inducing a toxic immune response by cross-linking the TCR and the major histocompatibility complex (MHC) class II and circumventing the antigen specificity. Here, we present the structure of staphylococcal enterotoxin E (SEE) in complex with a human T cell receptor, as well as the unligated T cell receptor structure. There are clear structural changes in the TCR loops upon superantigen binding. In particular, the HV4 loop moves to circumvent steric clashes upon complex formation. In addition, a predicted ternary model of SEE in complex with both TCR and MHC class II displays intermolecular contacts between the TCR alpha-chain and the MHC, suggesting that the TCR alpha-chain is of importance for complex formation.
PDB ID: 4UDUDownload
MMDB ID: 130281
PDB Deposition Date: 2014/12/11
Updated in MMDB: 2015/07
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Homo sapiens
Similar Structures:
Biological Unit for 4UDU: trimeric; determined by author and by software (PISA)
Molecular Components in 4UDU
Label Count Molecule
Proteins (3 molecules)
T Cell Receptor Alpha Chain, T-cell Receptor Alpha Chain C Region(Gene symbol: TRAC)
Molecule annotation
Protein Trbv7-9, T-cell Receptor Beta-2 Chain C Region(Gene symbol: TRBC2)
Molecule annotation
Enterotoxin Type E
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB