4YNQ image
Deposition Date 2015-03-10
Release Date 2015-05-27
Last Version Date 2025-02-12
Entry Detail
PDB ID:
4YNQ
Keywords:
Title:
TREX1-dsDNA complex
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.80 Å
R-Value Free:
0.26
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Three-prime repair exonuclease 1
Gene (Uniprot):Trex1
Mutations:D18N
Chain IDs:A, B, C, D
Chain Length:235
Number of Molecules:4
Biological Source:Mus musculus
Polymer Type:polydeoxyribonucleotide
Molecule:DNA (24-MER)
Chain IDs:E, G
Chain Length:21
Number of Molecules:2
Biological Source:synthetic construct
Polymer Type:polydeoxyribonucleotide
Molecule:DNA (5'-D(P*GP*TP*GP*CP*TP*GP*AP*CP*GP*TP*CP*AP*GP*CP*AP*CP*GP*AP*CP*G)-3')
Chain IDs:F, H
Chain Length:20
Number of Molecules:2
Biological Source:synthetic construct
Primary Citation
Exonuclease TREX1 degrades double-stranded DNA to prevent spontaneous lupus-like inflammatory disease.
Proc.Natl.Acad.Sci.USA 112 5117 5122 (2015)
PMID: 25848017 DOI: 10.1073/pnas.1423804112

Abstact

The TREX1 gene encodes a potent DNA exonuclease, and mutations in TREX1 cause a spectrum of lupus-like autoimmune diseases. Most lupus patients develop autoantibodies to double-stranded DNA (dsDNA), but the source of DNA antigen is unknown. The TREX1 D18N mutation causes a monogenic, cutaneous form of lupus called familial chilblain lupus, and the TREX1 D18N enzyme exhibits dysfunctional dsDNA-degrading activity, providing a link between dsDNA degradation and nucleic acid-mediated autoimmune disease. We determined the structure of the TREX1 D18N protein in complex with dsDNA, revealing how this exonuclease uses a novel DNA-unwinding mechanism to separate the polynucleotide strands for single-stranded DNA (ssDNA) loading into the active site. The TREX1 D18N dsDNA interactions coupled with catalytic deficiency explain how this mutant nuclease prevents dsDNA degradation. We tested the effects of TREX1 D18N in vivo by replacing the TREX1 WT gene in mice with the TREX1 D18N allele. The TREX1 D18N mice exhibit systemic inflammation, lymphoid hyperplasia, vasculitis, and kidney disease. The observed lupus-like inflammatory disease is associated with immune activation, production of autoantibodies to dsDNA, and deposition of immune complexes in the kidney. Thus, dysfunctional dsDNA degradation by TREX1 D18N induces disease in mice that recapitulates many characteristics of human lupus. Failure to clear DNA has long been linked to lupus in humans, and these data point to dsDNA as a key substrate for TREX1 and a major antigen source in mice with dysfunctional TREX1 enzyme.

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Protein

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Disease

Primary Citation of related structures