3QH3

The crystal structure of TCR A6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.19 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 

wwPDB Validation   3D Report Full Report



Literature

Disparate degrees of hypervariable loop flexibility control T-cell receptor cross-reactivity, specificity, and binding mechanism.

Scott, D.R.Borbulevych, O.Y.Piepenbrink, K.H.Corcelli, S.A.Baker, B.M.

(2011) J Mol Biol 414: 385-400

  • DOI: 10.1016/j.jmb.2011.10.006
  • Primary Citation of Related Structures:  
    3QFJ, 3QH3

  • PubMed Abstract: 
  • αβ T-cell receptors (TCRs) recognize multiple antigenic peptides bound and presented by major histocompatibility complex molecules. TCR cross-reactivity has been attributed in part to the flexibility of TCR complementarity-determining region (CDR) lo ...

    αβ T-cell receptors (TCRs) recognize multiple antigenic peptides bound and presented by major histocompatibility complex molecules. TCR cross-reactivity has been attributed in part to the flexibility of TCR complementarity-determining region (CDR) loops, yet there have been limited direct studies of loop dynamics to determine the extent of its role. Here we studied the flexibility of the binding loops of the αβ TCR A6 using crystallographic, spectroscopic, and computational methods. A significant role for flexibility in binding and cross-reactivity was indicated only for the CDR3α and CDR3β hypervariable loops. Examination of the energy landscapes of these two loops indicated that CDR3β possesses a broad, smooth energy landscape, leading to rapid sampling in the free TCR of a range of conformations compatible with different ligands. The landscape for CDR3α is more rugged, resulting in more limited conformational sampling that leads to specificity for a reduced set of peptides as well as the major histocompatibility complex protein. In addition to informing on the mechanisms of cross-reactivity and specificity, the energy landscapes of the two loops indicate a complex mechanism for TCR binding, incorporating elements of both conformational selection and induced fit in a manner that blends features of popular models for TCR recognition.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
A6 alpha chainAC194Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
A6 beta chainBD245Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
A, B, C, D
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

Download CCD File 
A, B, C, D
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.19 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 91.247α = 90
b = 51.735β = 105.05
c = 96.336γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
SBC-Collectdata collection
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-01-04
    Type: Initial release