8EB9

Crystal structure of SIX8 from Fusarium oxysporum f. sp. lycopersici

Summary for 8EB9

• Entry DOI: 10.2210/pdb8eb9/pdb
• Descriptor: Secreted in xylem Six8, SULFATE ION (3 entities in total)
• Functional Keywords: fungal effector, six8, unknown function
• Biological source: Fusarium oxysporum f. sp. lycopersici
• Total number of polymer chains: 1
• Total formula weight: 10057.34

Authors

Yu, D.S.,Ericsson, D.J.,Williams, S.J. (deposition date: 2022-08-30, release date: 2023-06-21, Last modification date: 2024-04-03)

Primary citation

Yu, D.S.,Outram, M.A.,Smith, A.,McCombe, C.L.,Khambalkar, P.B.,Rima, S.A.,Sun, X.,Ma, L.,Ericsson, D.J.,Jones, D.A.,Williams, S.J.
The structural repertoire of Fusarium oxysporum f. sp. lycopersici effectors revealed by experimental and computational studies.
Elife, 12:-, 2024

PubMed Abstract: Plant pathogens secrete proteins, known as effectors, that function in the apoplast or inside plant cells to promote virulence. Effector recognition by cell-surface or cytosolic receptors results in the activation of defence pathways and plant immunity. Despite their importance, our general understanding of fungal effector function and recognition by immunity receptors remains poor. One complication often associated with effectors is their high sequence diversity and lack of identifiable sequence motifs precluding prediction of structure or function. In recent years, several studies have demonstrated that fungal effectors can be grouped into structural classes, despite significant sequence variation and existence across taxonomic groups. Using protein X-ray crystallography, we identify a new structural class of effectors hidden within the secreted in xylem (SIX) effectors from f. sp. (). The recognised effectors Avr1 (SIX4) and Avr3 (SIX1) represent the founding members of the dual-domain (FOLD) effector class, with members containing two distinct domains. Using AlphaFold2, we predicted the full SIX effector repertoire of and show that SIX6 and SIX13 are also FOLD effectors, which we validated experimentally for SIX6. Based on structural prediction and comparisons, we show that FOLD effectors are present within three divisions of fungi and are expanded in pathogens and symbionts. Further structural comparisons demonstrate that secretes effectors that adopt a limited number of structural folds during infection of tomato. This analysis also revealed a structural relationship between transcriptionally co-regulated effector pairs. We make use of the Avr1 structure to understand its recognition by the I receptor, which leads to disease resistance in tomato. This study represents an important advance in our understanding of tomato, and by extension plant-fungal interactions, which will assist in the development of novel control and engineering strategies to combat plant pathogens.

PubMed: 38411527
DOI: 10.7554/eLife.89280

Experimental method

X-RAY DIFFRACTION (1.28 Å)