3H9H: Human Class I MHC HLA-A2(A150P) in complex with the Tel1p peptide

Citation:
Abstract
T cell-mediated immunity requires T cell receptor (TCR) cross-reactivity, the mechanisms behind which remain incompletely elucidated. The alphabeta TCR A6 recognizes both the Tax (LLFGYPVYV) and Tel1p (MLWGYLQYV) peptides presented by the human class I MHC molecule HLA-A2. Here we found that although the two ligands are ideal structural mimics, they form substantially different interfaces with A6, with conformational differences in the peptide, the TCR, and unexpectedly, the MHC molecule. The differences between the Tax and Tel1p ternary complexes could not be predicted from the free peptide-MHC structures and are inconsistent with a traditional induced-fit mechanism. Instead, the differences were attributable to peptide and MHC molecular motion present in Tel1p-HLA-A2 but absent in Tax-HLA-A2. Differential "tuning" of the dynamic properties of HLA-A2 by the Tax and Tel1p peptides thus facilitates cross-recognition and impacts how structural diversity can be presented to and accommodated by receptors of the immune system.
PDB ID: 3H9HDownload
MMDB ID: 79224
PDB Deposition Date: 2009/4/30
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Homo sapiens
Similar Structures:
Biological Unit for 3H9H: trimeric; determined by author and by software (PISA)
Molecular Components in 3H9H
Label Count Molecule
Proteins (3 molecules)
1
HLA Class I Histocompatibility Antigen, A-2 Alpha Chain(Gene symbol: HLA-A)
Molecule annotation
1
Beta-2-microglobulin(Gene symbol: B2M)
Molecule annotation
1
Tel1p Peptide
Molecule annotation
Chemicals (3 molecules)
1
2
2
1
Molecule information is not avaliable.
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Citing MMDB
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