SFI3 effector protein from the oomycete plant pathogen Phytophthora infestans

Experimental Data Snapshot

  • Resolution: 1.70 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.221 

wwPDB Validation   3D Report Full Report

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Phytophthora infestans effector SFI3 targets potato UBK to suppress early immune transcriptional responses.

He, Q.McLellan, H.Hughes, R.K.Boevink, P.C.Armstrong, M.Lu, Y.Banfield, M.J.Tian, Z.Birch, P.R.J.

(2019) New Phytol 222: 438-454

  • DOI: https://doi.org/10.1111/nph.15635
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The potato blight agent Phytophthora infestans secretes a range of RXLR effectors to promote disease. Recent evidence indicates that some effectors suppress early pattern-triggered immunity (PTI) following perception of microbe-associated molecular patterns (MAMPs). Phytophthora infestans effector PiSFI3/Pi06087/PexRD16 has been previously shown to suppress MAMP-triggered pFRK1-Luciferase reporter gene activity. How PiSFI3 suppresses immunity is unknown. We employed yeast-two-hybrid (Y2H) assays, co-immunoprecipitation, transcriptional silencing by RNA interference and virus-induced gene silencing (VIGS), and X-ray crystallography for structure-guided mutagenesis, to investigate the function of PiSFI3 in targeting a plant U-box-kinase protein (StUBK) to suppress immunity. We discovered that PiSFI3 is active in the host nucleus and interacts in yeast and in planta with StUBK. UBK is a positive regulator of specific PTI pathways in both potato and Nicotiana benthamiana. Importantly, it contributes to early transcriptional responses that are suppressed by PiSFI3. PiSFI3 forms an unusual trans-homodimer. Mutation to disrupt dimerization prevents nucleolar localisation of PiSFI3 and attenuates both its interaction with StUBK and its ability to enhance P. infestans leaf colonisation. PiSFI3 is a 'WY-domain' RXLR effector that forms a novel trans-homodimer which is required for its ability to suppress PTI via interaction with the U-box-kinase protein StUBK.

  • Organizational Affiliation

    Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Key Laboratory of Potato Biology and Biotechnology, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Secreted RxLR effector peptide protein, putative
A, B
98Phytophthora infestans T30-4Mutation(s): 0 
Gene Names: PITG_06087
Find proteins for D0N6D2 (Phytophthora infestans (strain T30-4))
Explore D0N6D2 
Go to UniProtKB:  D0N6D2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupD0N6D2
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.70 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.221 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 43.08α = 90
b = 44.39β = 90
c = 62.05γ = 90
Software Package:
Software NamePurpose
xia2data reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research CouncilUnited Kingdom--

Revision History  (Full details and data files)

  • Version 1.0: 2018-12-05
    Type: Initial release
  • Version 1.1: 2019-04-24
    Changes: Data collection, Database references
  • Version 1.2: 2024-05-15
    Changes: Advisory, Data collection, Database references