3QFD

Human Class I MHC HLA-A2 in complex with Mart-1(27-35) nonameric peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.68 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.172 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Loss of T Cell Antigen Recognition Arising from Changes in Peptide and Major Histocompatibility Complex Protein Flexibility: IMPLICATIONS FOR VACCINE DESIGN.

Insaidoo, F.K.Borbulevych, O.Y.Hossain, M.Santhanagopolan, S.M.Baxter, T.K.Baker, B.M.

(2011) J Biol Chem 286: 40163-40173

  • DOI: 10.1074/jbc.M111.283564
  • Primary Citation of Related Structures:  
    3QFD

  • PubMed Abstract: 
  • Modification of the primary anchor positions of antigenic peptides to improve binding to major histocompatibility complex (MHC) proteins is a commonly used strategy for engineering peptide-based vaccine candidates. However, such peptide modifications do not always improve antigenicity, complicating efforts to design effective vaccines for cancer and infectious disease ...

    Modification of the primary anchor positions of antigenic peptides to improve binding to major histocompatibility complex (MHC) proteins is a commonly used strategy for engineering peptide-based vaccine candidates. However, such peptide modifications do not always improve antigenicity, complicating efforts to design effective vaccines for cancer and infectious disease. Here we investigated the MART-1(27-35) tumor antigen, for which anchor modification (replacement of the position two alanine with leucine) dramatically reduces or ablates antigenicity with a wide range of T cell clones despite significantly improving peptide binding to MHC. We found that anchor modification in the MART-1(27-35) antigen enhances the flexibility of both the peptide and the HLA-A*0201 molecule. Although the resulting entropic effects contribute to the improved binding of the peptide to MHC, they also negatively impact T cell receptor binding to the peptide·MHC complex. These results help explain how the "anchor-fixing" strategy fails to improve antigenicity in this case, and more generally, may be relevant for understanding the high specificity characteristic of the T cell repertoire. In addition to impacting vaccine design, modulation of peptide and MHC flexibility through changes to antigenic peptides may present an evolutionary strategy for the escape of pathogens from immune destruction.


    Organizational Affiliation

    Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana 46556, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
HLA class I histocompatibility antigen, A-2 alpha chainA, D275Homo sapiensMutation(s): 0 
Gene Names: HLA-AHLAA
UniProt & NIH Common Fund Data Resources
Find proteins for P04439 (Homo sapiens)
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Go to UniProtKB:  P04439
PHAROS:  P04439
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Beta-2-microglobulinB, E100Homo sapiensMutation(s): 0 
Gene Names: B2MCDABP0092HDCMA22P
UniProt & NIH Common Fund Data Resources
Find proteins for P61769 (Homo sapiens)
Explore P61769 
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PHAROS:  P61769
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Mart-1(27-35) peptideC, F9N/AMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q16655 (Homo sapiens)
Explore Q16655 
Go to UniProtKB:  Q16655
PHAROS:  Q16655
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.68 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.172 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.254α = 90
b = 84.118β = 90.05
c = 83.964γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
MOLREPphasing
REFMACrefinement
PDB_EXTRACTdata extraction
SBC-Collectdata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-09-28
    Type: Initial release
  • Version 1.1: 2011-10-05
    Changes: Database references
  • Version 1.2: 2011-12-14
    Changes: Database references