6EA6

Structure of VACV poxin 2'3' cGAMP-specific nuclease


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.160 
  • R-Value Observed: 0.160 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Viral and metazoan poxins are cGAMP-specific nucleases that restrict cGAS-STING signalling.

Eaglesham, J.B.Pan, Y.Kupper, T.S.Kranzusch, P.J.

(2019) Nature 566: 259-263

  • DOI: 10.1038/s41586-019-0928-6
  • Primary Citation of Related Structures:  
    6EA6, 6EA8, 6EA9

  • PubMed Abstract: 
  • Cytosolic DNA triggers innate immune responses through the activation of cyclic GMP-AMP synthase (cGAS) and production of the cyclic dinucleotide second messenger 2',3'-cyclic GMP-AMP (cGAMP) 1-4 . 2',3'-cGAMP is a potent inducer of immune signalling; however, no intracellular nucleases are known to cleave 2',3'-cGAMP and prevent the activation of the receptor stimulator of interferon genes (STING) 5-7 ...

    Cytosolic DNA triggers innate immune responses through the activation of cyclic GMP-AMP synthase (cGAS) and production of the cyclic dinucleotide second messenger 2',3'-cyclic GMP-AMP (cGAMP) 1-4 . 2',3'-cGAMP is a potent inducer of immune signalling; however, no intracellular nucleases are known to cleave 2',3'-cGAMP and prevent the activation of the receptor stimulator of interferon genes (STING) 5-7 . Here we develop a biochemical screen to analyse 24 mammalian viruses, and identify poxvirus immune nucleases (poxins) as a family of 2',3'-cGAMP-degrading enzymes. Poxins cleave 2',3'-cGAMP to restrict STING-dependent signalling and deletion of the poxin gene (B2R) attenuates vaccinia virus replication in vivo. Crystal structures of vaccinia virus poxin in pre- and post-reactive states define the mechanism of selective 2',3'-cGAMP degradation through metal-independent cleavage of the 3'-5' bond, converting 2',3'-cGAMP into linear Gp[2'-5']Ap[3']. Poxins are conserved in mammalian poxviruses. In addition, we identify functional poxin homologues in the genomes of moths and butterflies and the baculoviruses that infect these insects. Baculovirus and insect host poxin homologues retain selective 2',3'-cGAMP degradation activity, suggesting an ancient role for poxins in cGAS-STING regulation. Our results define poxins as a family of 2',3'-cGAMP-specific nucleases and demonstrate a mechanism for how viruses evade innate immunity.


    Organizational Affiliation

    Parker Institute for Cancer Immunotherapy, Dana-Farber Cancer Institute, Boston, MA, USA. philip_kranzusch@dfci.harvard.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein B2A, C [auth B], B [auth C], D220Vaccinia virus WRMutation(s): 0 
Gene Names: VACWR184B2R
EC: 3.1
UniProt
Find proteins for Q01225 (Vaccinia virus (strain Western Reserve))
Explore Q01225 
Go to UniProtKB:  Q01225
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B [auth C], C [auth B], DL-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.160 
  • R-Value Observed: 0.160 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.026α = 90
b = 93.194β = 105.63
c = 94.133γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-02-06
    Type: Initial release
  • Version 1.1: 2019-02-20
    Changes: Data collection, Database references
  • Version 1.2: 2019-02-27
    Changes: Data collection, Database references
  • Version 1.3: 2019-12-11
    Changes: Derived calculations