Crystal structure of HearNPV P26

Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.185 

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Dual roles and evolutionary implications of P26/poxin in antagonizing intracellular cGAS-STING and extracellular melanization immunity.

Yin, M.Kuang, W.Wang, Q.Wang, X.Yuan, C.Lin, Z.Zhang, H.Deng, F.Jiang, H.Gong, P.Zou, Z.Hu, Z.Wang, M.

(2022) Nat Commun 13: 6934-6934

  • DOI: https://doi.org/10.1038/s41467-022-34761-0
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    P26, a homolog of the viral-encoded nuclease poxin that neutralizes the cGAS-STING innate immunity, is widely distributed in various invertebrate viruses, lepidopteran insects, and parasitoid wasps. P26/poxin from certain insect viruses also retains protease activity, though its biological role remains unknown. Given that many P26s contain a signal peptide, it is surmised that P26 may possess certain extracellular functions. Here, we report that a secretory baculoviral P26 suppresses melanization, a prominent insect innate immunity against pathogen invasion. P26 targets the cofactor of a prophenoloxidase-activating protease, and its inhibitory function is independent of nuclease activity. The analysis of P26/poxin homologs from different origins suggests that the ability to inhibit the extracellular melanization pathway is limited to P26s with a signal peptide and not shared by the homologs without it. These findings highlight the independent evolution of a single viral suppressor to perform dual roles in modulating immunity during virus-host adaptation.

  • Organizational Affiliation

    State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
299Helicoverpa armigera nucleopolyhedrovirus G4Mutation(s): 0 
Find proteins for Q99H25 (Helicoverpa armigera nucleopolyhedrovirus G4)
Explore Q99H25 
Go to UniProtKB:  Q99H25
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ99H25
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.90 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.185 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 194.749α = 90
b = 69.236β = 102.18
c = 52.746γ = 90
Software Package:
Software NamePurpose
HKL-2000data scaling
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China32170156

Revision History  (Full details and data files)

  • Version 1.0: 2022-11-23
    Type: Initial release
  • Version 1.1: 2023-01-11
    Changes: Database references