6EQA | pdb_00006eqa

HLA class I histocompatibility antigen


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.16 Å
  • R-Value Free: 
    0.263 (Depositor), 0.251 (DCC) 
  • R-Value Work: 
    0.186 (Depositor), 0.188 (DCC) 
  • R-Value Observed: 
    0.190 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 6EQA

This is version 1.3 of the entry. See complete history

Literature

TCR-induced alteration of primary MHC peptide anchor residue.

Madura, F.Rizkallah, P.J.Legut, M.Holland, C.J.Fuller, A.Bulek, A.Schauenburg, A.J.Trimby, A.Hopkins, J.R.Wells, S.A.Godkin, A.Miles, J.J.Sami, M.Li, Y.Liddy, N.Jakobsen, B.K.Loveridge, E.J.Cole, D.K.Sewell, A.K.

(2019) Eur J Immunol 49: 1052-1066

  • DOI: https://doi.org/10.1002/eji.201948085
  • Primary Citation Related Structures: 
    6EQA, 6EQB

  • PubMed Abstract: 

    The HLA-A*02:01-restricted decapeptide EAAGIGILTV, derived from melanoma antigen recognized by T-cells-1 (MART-1) protein, represents one of the best-studied tumor associated T-cell epitopes, but clinical results targeting this peptide have been disappointing. This limitation may reflect the dominance of the nonapeptide, AAGIGILTV, at the melanoma cell surface. The decapeptide and nonapeptide are presented in distinct conformations by HLA-A*02:01 and TCRs from clinically relevant T-cell clones recognize the nonapeptide poorly. Here, we studied the MEL5 TCR that potently recognizes the nonapeptide. The structure of the MEL5-HLA-A*02:01-AAGIGILTV complex revealed an induced fit mechanism of antigen recognition involving altered peptide-MHC anchoring. This "flexing" at the TCR-peptide-MHC interface to accommodate the peptide antigen explains previously observed incongruences in this well-studied system and has important implications for future therapeutic approaches. Finally, this study expands upon the mechanisms by which molecular plasticity can influence antigen recognition by T cells.


  • Organizational Affiliation
    • School of Medicine, Cardiff University, Cardiff, UK.

Macromolecule Content 

  • Total Structure Weight: 93.66 kDa 
  • Atom Count: 6,627 
  • Modeled Residue Count: 823 
  • Deposited Residue Count: 823 
  • Unique protein chains: 5

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
HLA class I histocompatibility antigen, A-2 alpha chain276Homo sapiensMutation(s): 0 
Gene Names: HLA-AHLAA
UniProt & NIH Common Fund Data Resources
Find proteins for P04439 (Homo sapiens)
Explore P04439 
Go to UniProtKB:  P04439
PHAROS:  P04439
GTEx:  ENSG00000206503 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04439
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Beta-2-microglobulin100Homo sapiensMutation(s): 0 
Gene Names: B2MCDABP0092HDCMA22P
UniProt & NIH Common Fund Data Resources
Find proteins for P61769 (Homo sapiens)
Explore P61769 
Go to UniProtKB:  P61769
PHAROS:  P61769
GTEx:  ENSG00000166710 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP61769
Sequence Annotations
Expand
Reference Sequence
Find similar proteins by:  Sequence   |   3D Structure  
Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
ALA-ALA-GLY-ILE-GLY-ILE-LEU-THR-VAL9Homo sapiensMutation(s): 0 
Find similar proteins by:|  3D Structure
Entity ID: 4
MoleculeChains  Sequence LengthOrganismDetailsImage
Mel5 TCR, alpha chain194Homo sapiensMutation(s): 0 
Find similar proteins by:|  3D Structure
Entity ID: 5
MoleculeChains  Sequence LengthOrganismDetailsImage
Mel5 TCR, beta chain244Homo sapiensMutation(s): 0 

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.16 Å
  • R-Value Free:  0.263 (Depositor), 0.251 (DCC) 
  • R-Value Work:  0.186 (Depositor), 0.188 (DCC) 
  • R-Value Observed: 0.190 (Depositor) 
Space Group: P 43
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 121.4α = 90
b = 121.4β = 90
c = 82.32γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
SCALAdata scaling
PHASERphasing
PDB_EXTRACTdata extraction
XDSdata reduction
xia2data reduction

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
United Kingdom--

Revision History  (Full details and data files)

  • Version 1.0: 2018-10-10
    Type: Initial release
  • Version 1.1: 2019-10-23
    Changes: Data collection, Database references, Structure summary
  • Version 1.2: 2024-01-17
    Changes: Data collection, Database references, Refinement description
  • Version 1.3: 2024-11-13
    Changes: Structure summary