5N6I

Crystal structure of mouse cGAS in complex with 39 bp DNA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.6 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

cGAS senses long and HMGB/TFAM-bound U-turn DNA by forming protein-DNA ladders.

Andreeva, L.Hiller, B.Kostrewa, D.Lassig, C.de Oliveira Mann, C.C.Jan Drexler, D.Maiser, A.Gaidt, M.Leonhardt, H.Hornung, V.Hopfner, K.P.

(2017) Nature 549: 394-398

  • DOI: 10.1038/nature23890

  • PubMed Abstract: 
  • Cytosolic DNA arising from intracellular pathogens triggers a powerful innate immune response. It is sensed by cyclic GMP-AMP synthase (cGAS), which elicits the production of type I interferons by generating the second messenger 2'3'-cyclic-GMP-AMP ( ...

    Cytosolic DNA arising from intracellular pathogens triggers a powerful innate immune response. It is sensed by cyclic GMP-AMP synthase (cGAS), which elicits the production of type I interferons by generating the second messenger 2'3'-cyclic-GMP-AMP (cGAMP). Endogenous nuclear or mitochondrial DNA can also be sensed by cGAS under certain conditions, resulting in sterile inflammation. The cGAS dimer binds two DNA ligands shorter than 20 base pairs side-by-side, but 20-base-pair DNA fails to activate cGAS in vivo and is a poor activator in vitro. Here we show that cGAS is activated in a strongly DNA length-dependent manner both in vitro and in human cells. We also show that cGAS dimers form ladder-like networks with DNA, leading to cooperative sensing of DNA length: assembly of the pioneering cGAS dimer between two DNA molecules is ineffective; but, once formed, it prearranges the flanking DNA to promote binding of subsequent cGAS dimers. Remarkably, bacterial and mitochondrial nucleoid proteins HU and mitochondrial transcription factor A (TFAM), as well as high-mobility group box 1 protein (HMGB1), can strongly stimulate long DNA sensing by cGAS. U-turns and bends in DNA induced by these proteins pre-structure DNA to nucleate cGAS dimers. Our results suggest a nucleation-cooperativity-based mechanism for sensitive detection of mitochondrial DNA and pathogen genomes, and identify HMGB/TFAM proteins as DNA-structuring host factors. They provide an explanation for the peculiar cGAS dimer structure and suggest that cGAS preferentially binds incomplete nucleoid-like structures or bent DNA.


    Organizational Affiliation

    Department of Biochemistry, Ludwig-Maximilians-Universit√§t M√ľnchen, 81377 Munich, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cyclic GMP-AMP synthase
A, B, C, D, E, F
370Mus musculusGene Names: Mb21d1
EC: 2.7.7.86
Find proteins for Q8C6L5 (Mus musculus)
Go to UniProtKB:  Q8C6L5
Entity ID: 2
MoleculeChainsLengthOrganism
DNA (37-MER)G,I,K,M39synthetic construct
Entity ID: 3
MoleculeChainsLengthOrganism
DNA (36-MER)H,J,L,N39synthetic construct
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B, C, D, E, F
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.6 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.204 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 168.530α = 90.00
b = 122.940β = 96.37
c = 179.980γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
STARANISOdata scaling
PHASERphasing
XSCALEdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationCountryGrant Number
German Research FoundationGermanyHO2489/8-1
the Center for Integrated Protein SciencesGermany--

Revision History 

  • Version 1.0: 2017-09-13
    Type: Initial release
  • Version 1.1: 2017-09-27
    Type: Database references
  • Version 1.2: 2017-10-04
    Type: Database references