6GU1

SFI3 effector protein from the oomycete plant pathogen Phytophthora infestans

Summary for 6GU1

• Entry DOI: 10.2210/pdb6gu1/pdb
• Descriptor: Secreted RxLR effector peptide protein, putative (2 entities in total)
• Functional Keywords: effector protein, unknown function
• Biological source: Phytophthora infestans (strain T30-4) (Potato late blight fungus)
• Total number of polymer chains: 2
• Total formula weight: 22521.80

Authors

Hughes, R.K.,Banfield, M.J. (deposition date: 2018-06-19, release date: 2018-12-05, Last modification date: 2024-05-15)

Primary citation

He, Q.,McLellan, H.,Hughes, R.K.,Boevink, P.C.,Armstrong, M.,Lu, Y.,Banfield, M.J.,Tian, Z.,Birch, P.R.J.
Phytophthora infestans effector SFI3 targets potato UBK to suppress early immune transcriptional responses.
New Phytol., 222:438-454, 2019

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.

PubMed: 30536576
DOI: 10.1111/nph.15635

Experimental method

X-RAY DIFFRACTION (1.7 Å)