6DFQ

mouse diabetogenic TCR I.29


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 

wwPDB Validation   3D Report Full Report


This is version 1.0 of the entry. See complete history


Literature

How C-terminal additions to insulin B-chain fragments create superagonists for T cells in mouse and human type 1 diabetes.

Wang, Y.Sosinowski, T.Novikov, A.Crawford, F.White, J.Jin, N.Liu, Z.Zou, J.Neau, D.Davidson, H.W.Nakayama, M.Kwok, W.W.Gapin, L.Marrack, P.Kappler, J.W.Dai, S.

(2019) Sci Immunol 4

  • DOI: 10.1126/sciimmunol.aav7517
  • Primary Citation of Related Structures:  
    6DFQ, 6DFS, 6DFW, 6DFV, 6DFX

  • PubMed Abstract: 
  • In type 1 diabetes (T1D), proinsulin is a major autoantigen and the insulin B:9-23 peptide contains epitopes for CD4 + T cells in both mice and humans. This peptide requires carboxyl-terminal mutations for uniform binding in the proper position within the mouse IA g7 or human DQ8 major histocompatibility complex (MHC) class II (MHCII) peptide grooves and for strong CD4 + T cell stimulation ...

    In type 1 diabetes (T1D), proinsulin is a major autoantigen and the insulin B:9-23 peptide contains epitopes for CD4 + T cells in both mice and humans. This peptide requires carboxyl-terminal mutations for uniform binding in the proper position within the mouse IA g7 or human DQ8 major histocompatibility complex (MHC) class II (MHCII) peptide grooves and for strong CD4 + T cell stimulation. Here, we present crystal structures showing how these mutations control CD4 + T cell receptor (TCR) binding to these MHCII-peptide complexes. Our data reveal stricking similarities between mouse and human CD4 + TCRs in their interactions with these ligands. We also show how fusions between fragments of B:9-23 and of proinsulin C-peptide create chimeric peptides with activities as strong or stronger than the mutated insulin peptides. We propose transpeptidation in the lysosome as a mechanism that could accomplish these fusions in vivo, similar to the creation of fused peptide epitopes for MHCI presentation shown to occur by transpeptidation in the proteasome. Were this mechanism limited to the pancreas and absent in the thymus, it could provide an explanation for how diabetogenic T cells escape negative selection during development but find their modified target antigens in the pancreas to cause T1D.


    Organizational Affiliation

    Structural Biology and Biochemistry program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
TCR alpha chainC [auth A], E [auth C], A [auth E], G210Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
TCR beta chainD [auth B], F [auth D], B [auth F], H242Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EDO
Query on EDO

Download Ideal Coordinates CCD File 
J [auth G], K [auth G]1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download Ideal Coordinates CCD File 
I [auth C]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.107α = 90
b = 117.629β = 90
c = 234.774γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

  • Deposited Date: 2018-05-15 
  • Released Date: 2019-04-17 
  • Deposition Author(s): Wang, Y., Dai, S.

Revision History  (Full details and data files)

  • Version 1.0: 2019-04-17
    Type: Initial release