3KXF image
Deposition Date 2009-12-03
Release Date 2010-06-09
Last Version Date 2024-10-30
Entry Detail
PDB ID:
3KXF
Keywords:
Title:
Crystal Structure of SB27 TCR in complex with the 'restriction triad' mutant HLA-B*3508-13mer
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
(Taxon ID: )
Host Organism:
Method Details:
Experimental Method:
Resolution:
3.10 Å
R-Value Free:
0.29
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:HLA class I histocompatibility antigen, B-35 alpha chain
Mutations:Q65A, T69A, Q155A
Chain IDs:A, C, I (auth: K), P (auth: I)
Chain Length:276
Number of Molecules:4
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Beta-2-microglobulin
Gene (Uniprot):B2M
Chain IDs:B, F, J (auth: L), Q (auth: J)
Chain Length:99
Number of Molecules:4
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:SB27 T cell receptor alpha chain
Chain IDs:D, G, K (auth: N), R (auth: M)
Chain Length:204
Number of Molecules:4
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:SB27 T cell receptor beta chain
Chain IDs:E, H, L (auth: P), S (auth: O)
Chain Length:241
Number of Molecules:4
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:peptide from Trans-activator protein BZLF1
Gene (Uniprot):BZLF1
Chain IDs:M (auth: Q), N (auth: R), O (auth: T), T (auth: S)
Chain Length:13
Number of Molecules:4
Biological Source:
Ligand Molecules
Primary Citation
Hard wiring of T cell receptor specificity for the major histocompatibility complex is underpinned by TCR adaptability
Proc.Natl.Acad.Sci.USA 107 10608 10613 (2010)
PMID: 20483993 DOI: 10.1073/pnas.1004926107

Abstact

alphabeta T cell receptors (TCRs) are genetically restricted to corecognize peptide antigens bound to self-major histocompatibility complex (pMHC) molecules; however, the basis for this MHC specificity remains unclear. Despite the current dogma, evaluation of the TCR-pMHC-I structural database shows that the nongermline-encoded complementarity-determining region (CDR)-3 loops often contact the MHC-I, and the germline-encoded CDR1 and -2 loops frequently participate in peptide-mediated interactions. Nevertheless, different TCRs adopt a roughly conserved docking mode over the pMHC-I, in which three MHC-I residues (65, 69, and 155) are invariably contacted by the TCR in one way or another. Nonetheless, the impact of mutations at these three positions, either individually or together, was not uniformly detrimental to TCR recognition of pHLA-B*0801 or pHLA-B*3508. Moreover, when TCR-pMHC-I recognition was impaired, this could be partially restored by expression of the CD8 coreceptor. The structure of a TCR-pMHC-I complex in which these three (65, 69, and 155) MHC-I positions were all mutated resulted in shifting of the TCR footprint relative to the cognate complex and formation of compensatory interactions. Collectively, our findings reveal the inherent adaptability of the TCR in maintaining peptide recognition while accommodating changes to the central docking site on the pMHC-I.

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Primary Citation of related structures