4LEZ

Structure of mouse cGAS bound to an 18bp DNA and cGAS product

• PDB DOI:  https://doi.org/10.2210/pdb4LEZ/pdb
• NAKB: 4LEZ

• Classification: TRANSFERASE/DNA
• Organism(s): Mus musculus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2013-06-26 Released: 2013-12-25 
• Deposition Author(s): Li, P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.36 Å
• R-Value Free: 0.247 
• R-Value Work: 0.192 
• R-Value Observed: 0.195 

Literature

Cyclic GMP-AMP Synthase Is Activated by Double-Stranded DNA-Induced Oligomerization.

Li, X., Shu, C., Yi, G., Chaton, C.T., Shelton, C.L., Diao, J., Zuo, X., Kao, C.C., Herr, A.B., Li, P.

(2013) Immunity 39: 1019-1031

• PubMed: 24332030 
• DOI: https://doi.org/10.1016/j.immuni.2013.10.019
• Primary Citation of Related Structures:  
  4LEV, 4LEW, 4LEY, 4LEZ


• PubMed Abstract: 
  

Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor mediating innate antimicrobial immunity. It catalyzes the synthesis of a noncanonical cyclic dinucleotide, 2',5' cGAMP, that binds to STING and mediates the activation of TBK1 and IRF-3. Activated IRF-3 translocates to the nucleus and initiates the transcription of the IFN-β gene. The structure of mouse cGAS bound to an 18 bp dsDNA revealed that cGAS interacts with dsDNA through two binding sites, forming a 2:2 complex. Enzyme assays and IFN-β reporter assays of cGAS mutants demonstrated that interactions at both DNA binding sites are essential for cGAS activation. Mutagenesis and DNA binding studies showed that the two sites bind dsDNA cooperatively and that site B plays a critical role in DNA binding. The structure of mouse cGAS bound to dsDNA and 2',5' cGAMP provided insight into the catalytic mechanism of cGAS. These results demonstrated that cGAS is activated by dsDNA-induced oligomerization.

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Organizational Affiliation: 

Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA. Electronic address: [e-mail].

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 109.51 kDa 
• Atom Count: 7,645 
• Modelled Residue Count: 790 
• Deposited Residue Count: 804 
• Unique protein chains: 1
• Unique nucleic acid chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cyclic GMP-AMP synthase	A, B [auth C]	366	Mus musculus	Mutation(s): 0  Gene Names: Mb21d1, Cgas EC: 2.7.7 (PDB Primary Data), 2.7.7.86 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for Q8C6L5 (Mus musculus) Explore Q8C6L5  Go to UniProtKB:  Q8C6L5
IMPC:  MGI:2442261

Entity ID: 2
Molecule	Chains	Length	Organism	Image
18bp dsDNA	C [auth E], D [auth F], E [auth I], F [auth J]	18	N/A

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
1SY	H [auth A], J [auth C]	cGAMP C20 H24 N10 O13 P2 XRILCFTWUCUKJR-INFSMZHSSA-N
ZN	G [auth A], I [auth C]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.36 Å
• R-Value Free: 0.247 
• R-Value Work: 0.192 
• R-Value Observed: 0.195 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 79.209	α = 90
b = 99.031	β = 90
c = 142.631	γ = 90

Software Package:

Software Name	Purpose
CrystalClear	data collection
PHASER	phasing
PHENIX	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2013-12-25 
Deposition Author(s): Li, P.

Revision History  

• Version 1.0: 2013-12-25
  Type: Initial release
  
• Version 1.1: 2014-01-08
  Changes: Database references
• Version 1.2: 2015-08-05
  Changes: Non-polymer description