3MBE

TCR 21.30 in complex with MHC class II I-Ag7HEL(11-27)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.886 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.253 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

The diabetogenic mouse MHC class II molecule I-Ag7 is endowed with a switch that modulates TCR affinity.

Yoshida, K.Corper, A.L.Herro, R.Jabri, B.Wilson, I.A.Teyton, L.

(2010) J.Clin.Invest. 120: 1578-1590

  • DOI: 10.1172/JCI41502

  • PubMed Abstract: 
  • Genetic susceptibility to autoimmunity is frequently associated with specific MHC alleles. Diabetogenic MHC class II molecules, such as human HLA-DQ8 and mouse I-Ag7, typically have a small, uncharged amino acid residue at position 57 of their beta c ...

    Genetic susceptibility to autoimmunity is frequently associated with specific MHC alleles. Diabetogenic MHC class II molecules, such as human HLA-DQ8 and mouse I-Ag7, typically have a small, uncharged amino acid residue at position 57 of their beta chain (beta57); this results in the absence of a salt bridge between beta57 and Argalpha76, which is adjacent to the P9 pocket of the peptide-binding groove. However, the influence of Argalpha76 on the selection of the TCR repertoire remains unknown, particularly when the MHC molecule binds a peptide with a neutral amino acid residue at position P9. Here, we have shown that diabetogenic MHC class II molecules bound to a peptide with a neutral P9 residue primarily selected and expanded cells expressing TCRs bearing a negatively charged residue in the first segment of their complementarity determining region 3beta. The crystal structure of one such TCR in complex with I-Ag7 bound to a peptide containing a neutral P9 residue revealed that a network of favorable long-range (greater than 4 A) electrostatic interactions existed among Argalpha76, the neutral P9 residue, and TCR, which supported the substantially increased TCR/peptide-MHC affinity. This network could be modulated or switched to a lower affinity interaction by the introduction of a negative charge at position P9 of the peptide. Our results support the existence of a switch at residue beta57 of the I-Ag7 and HLA-DQ8 class II molecules and potentially link normal thymic TCR selection with abnormal peripheral behavior.


    Organizational Affiliation

    Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
MHC CLASS II H2-IAg7 ALPHA CHAIN
A, E
190Mus musculusMutation(s): 0 
Gene Names: H2-Aa
Find proteins for P04228 (Mus musculus)
Go to UniProtKB:  P04228
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
MHC CLASS II H2-IAg7 BETA CHAIN
B, F
201Mus musculusMutation(s): 0 
Gene Names: H2-Ab1
Find proteins for Q31135 (Mus musculus)
Go to UniProtKB:  Q31135
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
PEPTIDE HEL 11-27
P, Q
18Gallus gallusMutation(s): 0 
Gene Names: LYZ
EC: 3.2.1.17
Find proteins for P00698 (Gallus gallus)
Go to Gene View: LYZ
Go to UniProtKB:  P00698
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
TCR 21.3 alpha chain
C, G
229Mus musculusMutation(s): 0 
Gene Names: Tcra
Find proteins for P01849 (Mus musculus)
Go to UniProtKB:  P01849
Entity ID: 5
MoleculeChainsSequence LengthOrganismDetails
TCR 21.3 beta chain
D, H
259Mus musculusMutation(s): 0 
Find proteins for P01852 (Mus musculus)
Go to UniProtKB:  P01852
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, D, E, H
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.886 Å
  • R-Value Free: 0.281 
  • R-Value Work: 0.253 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 67.468α = 90.00
b = 99.391β = 90.00
c = 404.677γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
XPREPdata reduction
Blu-Icedata collection
PHASERphasing
HKL-2000data reduction
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-05-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2013-04-10
    Type: Structure summary
  • Version 1.3: 2013-05-15
    Type: Database references, Source and taxonomy
  • Version 1.4: 2018-01-24
    Type: Structure summary