Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 26.18 kDa 
• Atom Count: 1766 
• Modelled Residue Count: 215 
• Deposited Residue Count: 243 
• Unique protein chains: 1

7TQN

Structure of human TREX1

• PDB DOI: 10.2210/pdb7TQN/pdb

• Classification: HYDROLASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2022-01-26 Released: 2022-08-03 
• Deposition Author(s): Zhou, W., Richmond-Buccola, D., Kranzusch, P.J.
• Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.208 
• R-Value Work: 0.175 
• R-Value Observed: 0.178 

Literature

Structural basis of human TREX1 DNA degradation and autoimmune disease.

Zhou, W., Richmond-Buccola, D., Wang, Q., Kranzusch, P.J.

(2022) Nat Commun 13: 4277-4277

• PubMed: 35879334 
• DOI: 10.1038/s41467-022-32055-z
• Primary Citation of Related Structures:  
  7TQN, 7TQO, 7TQP, 7TQQ


• PubMed Abstract: 
  

TREX1 is a cytosolic DNA nuclease essential for regulation of cGAS-STING immune signaling. Existing structures of mouse TREX1 establish a mechanism of DNA degradation and provide a key model to explain autoimmune disease, but these structures incompletely explain human disease-associated mutations and have limited ability to guide development of small-molecule therapeutics. Here we determine crystal structures of human TREX1 in apo and DNA-bound conformations that provide high-resolution detail of all human-specific features. A 1.25 Å structure of human TREX1 establishes a complete model of solvation of the exonuclease active site and a 2.2 Å structure of the human TREX1-DNA complex enables identification of specific substitutions involved in DNA recognition. We map each TREX1 mutation associated with autoimmune disease and establish distinct categories of substitutions predicted to impact enzymatic function, protein stability, and interaction with cGAS-DNA liquid droplets. Our results explain how human-specific substitutions regulate TREX1 function and provide a foundation for structure-guided design of TREX1 therapeutics.

---

Organizational Affiliation: 

Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA, 02115, USA. [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Three-prime repair exonuclease 1	A	243	Homo sapiens	Mutation(s): 3  Gene Names: TREX1 EC: 3.1.11.2
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NSU2 (Homo sapiens) Explore Q9NSU2  Go to UniProtKB:  Q9NSU2
PHAROS:  Q9NSU2

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.208 
• R-Value Work: 0.175 
• R-Value Observed: 0.178 
• Space Group: P 4₁ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 57.081	α = 90
b = 57.081	β = 90
c = 123.117	γ = 90

Software Package:

Software Name	Purpose
PHENIX	refinement
XDS	data reduction
Aimless	data scaling
PHASER	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2022-01-26 
• Released Date: 2022-08-03 
Deposition Author(s): Zhou, W., Richmond-Buccola, D., Kranzusch, P.J.

---

Funding Organization	Location	Grant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	1DP2GM146250-01

Revision History  

• Version 1.0: 2022-08-03
  Type: Initial release