5MV4 image
Deposition Date 2017-01-15
Release Date 2017-07-19
Last Version Date 2024-01-17
Entry Detail
PDB ID:
5MV4
Keywords:
IMMUNE SYSTEM
Title:
ACC1 Fab fragment in complex with citrullinated CII616-639 epitope of collagen type II (ptm23)
Biological Source:
Source Organism:
Mus musculus (Taxon ID: 10090)
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
2.90 Å
R-Value Free:
0.24
R-Value Work:
0.23
R-Value Observed:
0.23
Space Group:
P 1 21 1
5MV4 validation report
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:ACC1 antibody Fab fragment, heavy chain
Chain IDs:A, D (auth: C), G (auth: F), J (auth: I), M (auth: L), P (auth: O), S (auth: R), V (auth: U)
Chain Length:218
Number of Molecules:8
Biological Source:Mus musculus
Polymer Type:polypeptide(L)
Molecule:ACC1 antibody Fab fragment, light chain
Chain IDs:B, E (auth: D), H (auth: G), K (auth: J), N (auth: M), Q (auth: P), T (auth: S), W (auth: V)
Chain Length:218
Number of Molecules:8
Biological Source:Mus musculus
Protein Blast
Polymer Type:polypeptide(L)
Molecule:synthetic peptide containing the citrullinated collagen type II epitope CII616-639,Collagen alpha-1(II) chain,synthetic peptide containing the citrullinated collagen type II epitope CII616-639
Chain IDs:C (auth: X), F (auth: E), I (auth: H), L (auth: K), O (auth: N), R (auth: Q), U (auth: T), X (auth: W)
Chain Length:46
Number of Molecules:8
Biological Source:Mus musculus
UniProt ID:P02458 Pfam ID:PF01391
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
HYP C PRO modified residue
Ligand Molecules
SO4
Primary Citation
Anti-citrullinated protein antibodies cause arthritis by cross-reactivity to joint cartilage.
JCI Insight 2 ? ? (2017)
PMID: 28679953 DOI: 10.1172/jci.insight.93688

Abstact

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.

Legend

Protein

Chemical

Disease

Primary Citation of related structures
5MV4