Biological Assembly 1  

 3D View: Structure | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 9-mer - A2B2C2D2E1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 9-mer - A6B2C1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: surface plasmon resonance

Macromolecule Content

• Total Structure Weight: 242.82 kDa 
• Atom Count: 13969 
• Modelled Residue Count: 1333 
• Deposited Residue Count: 1646 
• Unique protein chains: 5
• Unique nucleic acid chains: 2

7A08

CryoEM Structure of cGAS Nucleosome complex

• DOI: 10.2210/pdb7A08/pdb
• EMDataResource: EMD-11601

• Classification: TRANSFERASE
• Organism(s): Mus musculus, synthetic construct, Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2020-08-07 Released: 2020-09-23 
• Deposition Author(s): Michalski, S., de Oliveira Mann, C.C., Witte, G., Bartho, J., Lammens, K., Hopfner, K.P.
• Funding Organization(s): German Research Foundation (DFG)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.11 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structural basis for sequestration and autoinhibition of cGAS by chromatin.

Michalski, S., de Oliveira Mann, C.C., Stafford, C.A., Witte, G., Bartho, J., Lammens, K., Hornung, V., Hopfner, K.P.

(2020) Nature 587: 678-682

• PubMed: 32911480 
• DOI: 10.1038/s41586-020-2748-0
• Primary Citation of Related Structures:  
  7A08


• PubMed Abstract: 
  

Cyclic GMP-AMP synthase (cGAS) is an innate immune sensor for cytosolic microbial DNA ¹ . After binding DNA, cGAS synthesizes the messenger 2'3'-cyclic GMP-AMP (cGAMP) ^2-4 , which triggers cell-autonomous defence and the production of type I interferons and pro-inflammatory cytokines via the activation of STING ⁵ . In addition to responding to cytosolic microbial DNA, cGAS also recognizes mislocalized cytosolic self-DNA and has been implicated in autoimmunity and sterile inflammation ^6,7 . Specificity towards pathogen- or damage-associated DNA was thought to be caused by cytosolic confinement. However, recent findings place cGAS robustly in the nucleus ^8-10 , where tight tethering of chromatin is important to prevent autoreactivity to self-DNA ⁸ . Here we show how cGAS is sequestered and inhibited by chromatin. We provide a cryo-electron microscopy structure of the cGAS catalytic domain bound to a nucleosome, which shows that cGAS does not interact with the nucleosomal DNA, but instead interacts with histone 2A-histone 2B, and is tightly anchored to the 'acidic patch'. The interaction buries the cGAS DNA-binding site B, and blocks the formation of active cGAS dimers. The acidic patch robustly outcompetes agonistic DNA for binding to cGAS, which suggests that nucleosome sequestration can efficiently inhibit cGAS, even when accessible DNA is nearby, such as in actively transcribed genomic regions. Our results show how nuclear cGAS is sequestered by chromatin and provides a mechanism for preventing autoreactivity to nuclear self-DNA.

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Organizational Affiliation: 

Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany. [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cyclic GMP-AMP synthase	A [auth a]	370	Mus musculus	Mutation(s): 0  Gene Names: Mb21d1, Cgas EC: 2.7.7.86
UniProt & NIH Common Fund Data Resources
Find proteins for Q8C6L5 (Mus musculus) Explore Q8C6L5  Go to UniProtKB:  Q8C6L5
IMPC:  MGI:2442261

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
Histone H2A type 1-C	D [auth b], H [auth f]	129	Homo sapiens	Mutation(s): 0  Gene Names: H2AC6, H2AFL, HIST1H2AC
UniProt & NIH Common Fund Data Resources
Find proteins for Q93077 (Homo sapiens) Explore Q93077  Go to UniProtKB:  Q93077
PHAROS:  Q93077 GTEx:  ENSG00000180573

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
Histone H2B type 1-C/E/F/G/I	E [auth c], I [auth g]	125	Homo sapiens	Mutation(s): 0  Gene Names:  HIST1H2BC, H2BFL, HIST1H2BE, H2BFH, HIST1H2BF, H2BFG, HIST1H2BG, H2BFA, HIST1H2BI, H2BFK, H2BC4, H2BC6, H2BC7, H2BC8, H2BC10
UniProt & NIH Common Fund Data Resources
Find proteins for P62807 (Homo sapiens) Explore P62807  Go to UniProtKB:  P62807
PHAROS:  P62807 GTEx:  ENSG00000180596ENSG00000277224ENSG00000278588ENSG00000273802ENSG00000274290

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
Histone H3.3	F [auth d], J [auth h]	135	Homo sapiens	Mutation(s): 0  Gene Names: H3-3A, H3.3A, H3F3, H3F3A, PP781, H3-3B, H3.3B, H3F3B
UniProt & NIH Common Fund Data Resources
Find proteins for P84243 (Homo sapiens) Explore P84243  Go to UniProtKB:  P84243
PHAROS:  P84243 GTEx:  ENSG00000163041

Entity ID: 7
Molecule	Chains	Sequence Length	Organism	Details	Image
Histone H4	G [auth e], K [auth i]	102	Homo sapiens	Mutation(s): 0  Gene Names:  HIST1H4A, H4/A, H4FA, HIST1H4B, H4/I, H4FI, HIST1H4C, H4/G, H4FG, HIST1H4D, H4/B, H4FB, HIST1H4E, H4/J, H4FJ, HIST1H4F, H4/C, H4FC, HIST1H4H, H4/H, H4FH, HIST1H4I, H4/M, H4FM, HIST1H4J, H4/E, H4FE, HIST1H4K, H4/D, H4FD, HIST1H4L, H4/K, H4FK, HIST2H4A, H4/N, H4F2, H4FN, HIST2H4, HIST2H4B, H4/O, H4FO, HIST4H4, H4C1, H4C2, H4C3, H4C4, H4C5, H4C6, H4C8, H4C9, H4C11, H4C12, H4C13, H4C14, H4C15, H4-16
UniProt & NIH Common Fund Data Resources
Find proteins for P62805 (Homo sapiens) Explore P62805  Go to UniProtKB:  P62805
PHAROS:  P62805 GTEx:  ENSG00000274618ENSG00000197238ENSG00000197837ENSG00000158406ENSG00000278705ENSG00000197061ENSG00000270882ENSG00000270276ENSG00000273542ENSG00000277157ENSG00000276966ENSG00000276180ENSG00000278637ENSG00000275126

Entity ID: 2
Molecule	Chains	Length	Organism	Image
Nucleosomal DNA strand 1	B [auth I]	147	synthetic construct

Entity ID: 3
Molecule	Chains	Length	Organism	Image
Nucleosomal DNA strand 2	C [auth J]	147	synthetic construct

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ZN	L [auth a]	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.11 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2020-08-07 
• Released Date: 2020-09-23 
Deposition Author(s): Michalski, S., de Oliveira Mann, C.C., Witte, G., Bartho, J., Lammens, K., Hopfner, K.P.

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Funding Organization	Location	Grant Number
German Research Foundation (DFG)	Germany	CRC/TRR237

Revision History  

• Version 1.0: 2020-09-23
  Type: Initial release
  
• Version 1.1: 2020-12-09
  Changes: Database references
• Version 1.2: 2021-02-10
  Changes: Source and taxonomy