4O68

Structure of human cyclic GMP-AMP synthase (cGAS)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.436 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The Cytosolic DNA Sensor cGAS Forms an Oligomeric Complex with DNA and Undergoes Switch-like Conformational Changes in the Activation Loop.

Zhang, X.Wu, J.Du, F.Xu, H.Sun, L.Chen, Z.Brautigam, C.A.Zhang, X.Chen, Z.J.

(2014) Cell Rep 6: 421-430

  • DOI: 10.1016/j.celrep.2014.01.003
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The presence of DNA in the cytoplasm is a danger signal that triggers immune and inflammatory responses. Cytosolic DNA binds to and activates cyclic GMP-AMP (cGAMP) synthase (cGAS), which produces the second messenger cGAMP. cGAMP binds to the adapto ...

    The presence of DNA in the cytoplasm is a danger signal that triggers immune and inflammatory responses. Cytosolic DNA binds to and activates cyclic GMP-AMP (cGAMP) synthase (cGAS), which produces the second messenger cGAMP. cGAMP binds to the adaptor protein STING and activates a signaling cascade that leads to the production of type I interferons and other cytokines. Here, we report the crystal structures of human cGAS in its apo form, representing its autoinhibited conformation as well as in its cGAMP- and sulfate-bound forms. These structures reveal switch-like conformational changes of an activation loop that result in the rearrangement of the catalytic site. The structure of DNA-bound cGAS reveals a complex composed of dimeric cGAS bound to two molecules of DNA. Functional analyses of cGAS mutants demonstrate that both the protein-protein interface and the two DNA binding surfaces are critical for cGAS activation. These results provide insights into the mechanism of DNA sensing by cGAS.


    Organizational Affiliation

    Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA. Electronic address: xu.zhang@utsouthwestern.edu.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cyclic GMP-AMP synthase
A
376Homo sapiensMutation(s): 0 
Gene Names: CGAS (C6orf150, MB21D1)
EC: 2.7.7.86
Find proteins for Q8N884 (Homo sapiens)
Go to UniProtKB:  Q8N884
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.436 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.180 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 162.194α = 90.00
b = 47.051β = 90.00
c = 58.404γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-02-05
    Type: Initial release
  • Version 1.1: 2014-03-05
    Type: Database references