PDBsum entry 3mbe

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Immune system PDB id
Protein chains
184 a.a. *
178 a.a. *
17 a.a. *
192 a.a. *
236 a.a. *
NAG ×2
* Residue conservation analysis
PDB id:
Name: Immune system
Title: Tcr 21.30 in complex with mhc class ii i-ag7hel(11-27)
Structure: Mhc class ii h2-iag7 alpha chain. Chain: a, e. Synonym: h-2 class ii histocompatibility antigen, a-d alpha engineered: yes. Mhc class ii h2-iag7 beta chain. Chain: b, f. Synonym: mhc class ii h2-ia-beta chain (haplotype nod). Engineered: yes. Peptide hel 11-27.
Source: Mus musculus. Mouse. Organism_taxid: 10090. Gene: h2-aa. Expressed in: drosophila melanogaster. Expression_system_taxid: 7227. Gene: h2-ab1. Synthetic: yes. Gallus gallus.
2.89Å     R-factor:   0.254     R-free:   0.281
Authors: A.L.Corper,K.Yoshida,L.Teyton,Wilson I.A.
Key ref: K.Yoshida et al. (2010). The diabetogenic mouse MHC class II molecule I-Ag7 is endowed with a switch that modulates TCR affinity. J Clin Invest, 120, 1578-1590. PubMed id: 20407212
25-Mar-10     Release date:   12-May-10    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P04228  (HA2D_MOUSE) -  H-2 class II histocompatibility antigen, A-D alpha chain
256 a.a.
184 a.a.*
Protein chains
Pfam   ArchSchema ?
Q31135  (Q31135_MOUSE) -  H2-Ab1 protein
263 a.a.
178 a.a.*
Protein chains
Pfam   ArchSchema ?
P00698  (LYSC_CHICK) -  Lysozyme C
147 a.a.
17 a.a.*
Protein chains
Pfam   ArchSchema ?
P01849  (TCA_MOUSE) -  T-cell receptor alpha chain C region
138 a.a.
192 a.a.*
Protein chains
Pfam   ArchSchema ?
P01852  (TCB1_MOUSE) -  T-cell receptor beta-1 chain C region
173 a.a.
236 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 10 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: Chains P, Q: E.C.  - Lysozyme.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Hydrolysis of the 1,4-beta-linkages between N-acetyl-D-glucosamine and N-acetylmuramic acid in peptidoglycan heteropolymers of the prokaryotes cell walls.
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     membrane   2 terms 
  Biological process     immune response   2 terms 


J Clin Invest 120:1578-1590 (2010)
PubMed id: 20407212  
The diabetogenic mouse MHC class II molecule I-Ag7 is endowed with a switch that modulates TCR affinity.
K.Yoshida, A.L.Corper, R.Herro, B.Jabri, I.A.Wilson, L.Teyton.
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.

Literature references that cite this PDB file's key reference

  PubMed id Reference
21364947 J.M.Khan, and S.Ranganathan (2011).
Understanding TR Binding to pMHC Complexes: How Does a TR Scan Many pMHC Complexes yet Preferentially Bind to One.
  PLoS One, 6, e17194.  
21219178 V.Abadie, L.M.Sollid, L.B.Barreiro, and B.Jabri (2011).
Integration of genetic and immunological insights into a model of celiac disease pathogenesis.
  Annu Rev Immunol, 29, 493-525.  
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