7CCR

Structure of the 2:2 cGAS-nucleosome complex


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.90 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis for nucleosome-mediated inhibition of cGAS activity.

Cao, D.Han, X.Fan, X.Xu, R.M.Zhang, X.

(2020) Cell Res 30: 1088-1097

  • DOI: 10.1038/s41422-020-00422-4
  • Primary Citation of Related Structures:  
    7CCQ, 7CCR

  • PubMed Abstract: 
  • Activation of cyclic GMP-AMP synthase (cGAS) through sensing cytosolic double stranded DNA (dsDNA) plays a pivotal role in innate immunity against exogenous infection as well as cellular regulation under stress. Aberrant activation of cGAS induced by self-DNA is related to autoimmune diseases ...

    Activation of cyclic GMP-AMP synthase (cGAS) through sensing cytosolic double stranded DNA (dsDNA) plays a pivotal role in innate immunity against exogenous infection as well as cellular regulation under stress. Aberrant activation of cGAS induced by self-DNA is related to autoimmune diseases. cGAS accumulates at chromosomes during mitosis or spontaneously in the nucleus. Binding of cGAS to the nucleosome competitively attenuates the dsDNA-mediated cGAS activation, but the molecular mechanism of the attenuation is still poorly understood. Here, we report two cryo-electron microscopy structures of cGAS-nucleosome complexes. The structures reveal that cGAS interacts with the nucleosome as a monomer, forming 1:1 and 2:2 complexes, respectively. cGAS contacts the nucleosomal acidic patch formed by the H2A-H2B heterodimer through the dsDNA-binding site B in both complexes, and could interact with the DNA from the other symmetrically placed nucleosome via the dsDNA-binding site C in the 2:2 complex. The bound nucleosome inhibits the activation of cGAS through blocking the interaction of cGAS with ligand dsDNA and disrupting cGAS dimerization. R236A or R255A mutation of cGAS impairs the binding between cGAS and the nucleosome, and largely relieves the nucleosome-mediated inhibition of cGAS activity. Our study provides structural insights into the inhibition of cGAS activity by the nucleosome, and advances the understanding of the mechanism by which hosts avoid the autoimmune attack caused by cGAS.


    Organizational Affiliation

    Center for Biological Imaging, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. xzzhang@ibp.ac.cn.



Macromolecules

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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Histone H3.1A, E, L, P98Homo sapiensMutation(s): 0 
Gene Names: 
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Find proteins for P68431 (Homo sapiens)
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PHAROS:  P68431
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UniProt GroupP68431
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Histone H4B, F, M, Q80Homo sapiensMutation(s): 0 
Gene Names: 
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Find proteins for P62805 (Homo sapiens)
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Histone H2A type 1-B/EC, G, N, R103Homo sapiensMutation(s): 0 
Gene Names: H2AC4H2AFMHIST1H2ABH2AC8H2AFAHIST1H2AE
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Find proteins for P04908 (Homo sapiens)
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Entity ID: 4
MoleculeChainsSequence LengthOrganismDetailsImage
Histone H2B type 1-JD, H, O, S93Homo sapiensMutation(s): 0 
Gene Names: H2BC11H2BFRHIST1H2BJ
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Find proteins for P06899 (Homo sapiens)
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GTEx:  ENSG00000124635 
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Entity ID: 7
MoleculeChainsSequence LengthOrganismDetailsImage
Cyclic GMP-AMP synthaseK, V366Homo sapiensMutation(s): 0 
Gene Names: CGASC6orf150MB21D1
EC: 2.7.7.86
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Find proteins for Q8N884 (Homo sapiens)
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GTEx:  ENSG00000164430 
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Entity ID: 5
MoleculeChainsLengthOrganismImage
DNA (147-MER)I, T 147Homo sapiens
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Entity ID: 6
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DNA (147-MER)J, U 147Homo sapiens
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Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.90 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Science and Technology (MoST, China)China2017YFA0504700
Ministry of Science and Technology (MoST, China)China2019YFA0508900
National Natural Science Foundation of China (NSFC)China31930069
National Natural Science Foundation of China (NSFC)China31521002
National Natural Science Foundation of China (NSFC)China31991162
Chinese Academy of SciencesChinaXDB37040101
Chinese Academy of SciencesChinaXDB37010101

Revision History  (Full details and data files)

  • Version 1.0: 2020-10-07
    Type: Initial release
  • Version 1.1: 2020-11-11
    Changes: Database references
  • Version 1.2: 2020-12-23
    Changes: Database references