5MU0

ACC1 Fab fragment in complex with citrullinated C1 epitope of CII (IA03)

  • Classification: IMMUNE SYSTEM
  • Organism(s): Mus musculus
  • Mutation(s): No 

  • Deposited: 2017-01-11 Released: 2017-07-19 
  • Deposition Author(s): Dobritzsch, D., Holmdahl, R., Ge, C.
  • Funding Organization(s): Swedish Foundation for Strategic Research, Knut and Alice Wallenberg Foundation, Swedish Research Council, European Union

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.252 
  • R-Value Observed: 0.253 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Anti-citrullinated protein antibodies cause arthritis by cross-reactivity to joint cartilage.

Ge, C.Tong, D.Liang, B.Lonnblom, E.Schneider, N.Hagert, C.Viljanen, J.Ayoglu, B.Stawikowska, R.Nilsson, P.Fields, G.B.Skogh, T.Kastbom, A.Kihlberg, J.Burkhardt, H.Dobritzsch, D.Holmdahl, R.

(2017) JCI Insight 2

  • DOI: 10.1172/jci.insight.93688
  • Primary Citation of Related Structures:  
    5MU0, 5MU2, 5MV3, 5MV4, 5MUB

  • PubMed Abstract: 
  • Today, it is known that autoimmune diseases start a long time before clinical symptoms appear. Anti-citrullinated protein antibodies (ACPAs) appear many years before the clinical onset of rheumatoid arthritis (RA). However, it is still unclear if and ...

    Today, it is known that autoimmune diseases start a long time before clinical symptoms appear. Anti-citrullinated protein antibodies (ACPAs) appear many years before the clinical onset of rheumatoid arthritis (RA). However, it is still unclear if and how ACPAs are arthritogenic. To better understand the molecular basis of pathogenicity of ACPAs, we investigated autoantibodies reactive against the C1 epitope of collagen type II (CII) and its citrullinated variants. We found that these antibodies are commonly occurring in RA. A mAb (ACC1) against citrullinated C1 was found to cross-react with several noncitrullinated epitopes on native CII, causing proteoglycan depletion of cartilage and severe arthritis in mice. Structural studies by X-ray crystallography showed that such recognition is governed by a shared structural motif "RG-TG" within all the epitopes, including electrostatic potential-controlled citrulline specificity. Overall, we have demonstrated a molecular mechanism that explains how ACPAs trigger arthritis.


    Organizational Affiliation

    Center for Medical Immunopharmacology Research, Southern Medical University, Guangzhou, China.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
heavy chain of ACC1 antibody Fab fragmentACEGIKMO218Mus 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
light chain of ACC1 antibody Fab fragmentBDFHJLNP218Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
IA03 peptide containing the citrullinated C1 epitope of collagen type II,Collagen alpha-1(II) chain,IA03 peptide containing the citrullinated C1 epitope of collagen type IIQRSTUVWX18Mus musculusMutation(s): 0 
Gene Names: Col2a1
Find proteins for P28481 (Mus musculus)
Explore P28481 
Go to UniProtKB:  P28481
Protein Feature View
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  • Reference Sequence
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
CIR
Query on CIR
Q,R,S,T,U,V,W,XL-PEPTIDE LINKINGC6 H13 N3 O3ARG
HYP
Query on HYP
Q,R,S,T,U,V,W,XL-PEPTIDE LINKINGC5 H9 N O3PRO
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.70 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.252 
  • R-Value Observed: 0.253 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 87.147α = 92.75
b = 93.052β = 106.45
c = 121.751γ = 104.37
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Swedish Foundation for Strategic ResearchSwedenRBa08-0047
Swedish Foundation for Strategic ResearchSwedenRB13-015
Knut and Alice Wallenberg FoundationSwedenKAW 2010.0148
Swedish Research CouncilSwedenK2009-75SX-21029-01-3
Swedish Research CouncilSwedenK2012-75SX-22072-01-3
Swedish Research CouncilSwedenK2011-52X-07931-25-5
Swedish Research CouncilSweden2015-02662
European UnionIMI 115142

Revision History 

  • Version 1.0: 2017-07-19
    Type: Initial release
  • Version 1.1: 2017-09-13
    Changes: Author supporting evidence, Refinement description