6BIX

HLA-DRB1 in complex with citrullinated LL37 peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.169 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The interplay between citrullination and HLA-DRB1 polymorphism in shaping peptide binding hierarchies in Rheumatoid Arthritis.

Ting, Y.T.Petersen, J.Ramarathinam, S.H.Scally, S.W.Loh, K.L.Thomas, R.Suri, A.Baker, D.G.Purcell, A.W.Reid, H.H.Rossjohn, J.

(2018) J. Biol. Chem. --: --

  • DOI: 10.1074/jbc.RA117.001013
  • Primary Citation of Related Structures:  6BIJ, 6BIL, 6BIN, 6BIR, 6BIV, 6BIY, 6BIZ

  • PubMed Abstract: 
  • The HLA-DRB1 locus is strongly associated with rheumatoid arthritis (RA) susceptibility, whereupon citrullinated self-peptides bind to HLA-DR molecules bearing the shared epitope (SE) amino acid motif.  However, the differing propensity for citrullin ...

    The HLA-DRB1 locus is strongly associated with rheumatoid arthritis (RA) susceptibility, whereupon citrullinated self-peptides bind to HLA-DR molecules bearing the shared epitope (SE) amino acid motif.  However, the differing propensity for citrullinated/non-citrullinated self-peptides to bind given HLA-DR allomorphs remains unclear.  Here, we used a fluorescence polarisation assay to determine a hierarchy of binding affinities of 34 self-peptides implicated in RA against three HLA-DRB1 allomorphs (HLA-DRB1*04:01/*04:04/*04:05) each possessing the SE motif. For all three HLA-DRB1 allomorphs, we observed a strong correlation between binding affinity and citrullination at P4 of the bound peptide ligand. A differing hierarchy of peptide-binding affinities across the three HLA-DRB1 allomorphs was attributable to the b-chain polymorphisms that resided outside the SE motif and were consistent with sequences of naturally presented peptide ligands. Structure determination of eight HLA-DR4-self-epitope complexes revealed strict conformational convergence of the P4-Cit and surrounding HLA b-chain residues. Polymorphic residues that form part of the P1 and P9 pockets of the HLA-DR molecules provided a structural basis for the preferential binding of the citrullinated self-peptides to the HLA-DR4 allomorphs. Collectively, we provide a molecular basis for the interplay between citrullination of self-antigens and HLA polymorphisms that shape peptide-HLA-DR4 binding affinities in RA.


    Organizational Affiliation

    Monash University, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DR alpha chain
A
189Homo 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 DR-beta (HLA-DR B)
B
200N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
LL37_Cit91
C
13N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CIR
Query on CIR
C
L-PEPTIDE LINKINGC6 H13 N3 O3ARG
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.169 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 67.337α = 90.00
b = 183.059β = 90.00
c = 78.435γ = 90.00
Software Package:
Software NamePurpose
Aimlessdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction
PHASERphasing
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2018-01-17
    Type: Initial release
  • Version 1.1: 2018-01-24
    Type: Database references, Structure summary