3T0E

Crystal structure of a complete ternary complex of T cell receptor, peptide-MHC and CD4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 4 Å
  • R-Value Free: 0.305 
  • R-Value Work: 0.238 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of a complete ternary complex of T-cell receptor, peptide-MHC, and CD4.

Yin, Y.Wang, X.X.Mariuzza, R.A.

(2012) Proc.Natl.Acad.Sci.USA 109: 5405-5410

  • DOI: 10.1073/pnas.1118801109

  • PubMed Abstract: 
  • Adaptive immunity depends on specific recognition by a T-cell receptor (TCR) of an antigenic peptide bound to a major histocompatibility complex (pMHC) molecule on an antigen-presenting cell (APC). In addition, T-cell activation generally requires bi ...

    Adaptive immunity depends on specific recognition by a T-cell receptor (TCR) of an antigenic peptide bound to a major histocompatibility complex (pMHC) molecule on an antigen-presenting cell (APC). In addition, T-cell activation generally requires binding of this same pMHC to a CD4 or CD8 coreceptor. Here, we report the structure of a complete TCR-pMHC-CD4 ternary complex involving a human autoimmune TCR, a myelin-derived self-peptide bound to HLA-DR4, and CD4. The complex resembles a pointed arch in which TCR and CD4 are each tilted ∼65° relative to the T-cell membrane. By precluding direct contacts between TCR and CD4, the structure explains how TCR and CD4 on the T cell can simultaneously, yet independently, engage the same pMHC on the APC. The structure, in conjunction with previous mutagenesis data, places TCR-associated CD3εγ and CD3εδ subunits, which transmit activation signals to the T cell, inside the TCR-pMHC-CD4 arch, facing CD4. By establishing anchor points for TCR and CD4 on the T-cell membrane, the complex provides a basis for understanding how the CD4 coreceptor focuses TCR on MHC to guide TCR docking on pMHC during thymic T-cell selection.


    Organizational Affiliation

    W. M. Keck Laboratory for Structural Biology, Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DR alpha chain
A
182Homo sapiensGene Names: HLA-DRA (HLA-DRA1)
Find proteins for P01903 (Homo sapiens)
Go to Gene View: HLA-DRA
Go to UniProtKB:  P01903
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DRB1-4 beta chain
B
221Homo sapiensGene Names: HLA-DRB1
Find proteins for P13760 (Homo sapiens)
Go to Gene View: HLA-DRB1
Go to UniProtKB:  P13760
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
T-cell receptor alpha chain
C
206Homo sapiensGene Names: TRAC (TCRA)
Find proteins for P01848 (Homo sapiens)
Go to UniProtKB:  P01848
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
T-cell receptor beta chain
D
245Homo sapiensGene Names: TRBC2 (TCRBC2)
Find proteins for A0A5B9 (Homo sapiens)
Go to UniProtKB:  A0A5B9
Entity ID: 5
MoleculeChainsSequence LengthOrganismDetails
T-cell surface glycoprotein CD4
E
373Homo sapiensGene Names: CD4
Find proteins for P01730 (Homo sapiens)
Go to Gene View: CD4
Go to UniProtKB:  P01730
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 4 Å
  • R-Value Free: 0.305 
  • R-Value Work: 0.238 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 146.151α = 90.00
b = 146.151β = 90.00
c = 231.436γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
PHASERphasing
JBluIce-EPICSdata collection
CrystalCleardata reduction
CrystalCleardata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-03-07
    Type: Initial release
  • Version 1.1: 2012-04-25
    Type: Database references
  • Version 1.2: 2017-11-08
    Type: Advisory, Refinement description