6q40
A secreted LysM effector of the wheat pathogen Zymoseptoria tritici protects the fungal hyphae against chitinase hydrolysis through ligand-dependent polymerisation of LysM homodimers
Structural highlights
FunctionLYSM1_ZYMTI Secreted effector that enables the plant pathogenic fungus to manipulate host defenses for successful infection (PubMed:21467214). Binds chitin but not cellulose or xylan (PubMed:21467214, PubMed:32574207, PubMed:33797163). Chitin-induced polymerization of homodimers forms a contiguous Mg1LysM highly oligomeric super-complexe that is anchored to the chitin in the fungal cell wall to prevent hydrolysis by host chitinases (PubMed:21467214, PubMed:32574207).[1] [2] [3] Publication Abstract from PubMedPlants trigger immune responses upon recognition of fungal cell wall chitin, followed by the release of various antimicrobials, including chitinase enzymes that hydrolyze chitin. In turn, many fungal pathogens secrete LysM effectors that prevent chitin recognition by the host through scavenging of chitin oligomers. We previously showed that intrachain LysM dimerization of the Cladosporium fulvum effector Ecp6 confers an ultrahigh-affinity binding groove that competitively sequesters chitin oligomers from host immune receptors. Additionally, particular LysM effectors are found to protect fungal hyphae against chitinase hydrolysis during host colonization. However, the molecular basis for the protection of fungal cell walls against hydrolysis remained unclear. Here, we determined a crystal structure of the single LysM domain-containing effector Mg1LysM of the wheat pathogen Zymoseptoria tritici and reveal that Mg1LysM is involved in the formation of two kinds of dimers; a chitin-dependent dimer as well as a chitin-independent homodimer. In this manner, Mg1LysM gains the capacity to form a supramolecular structure by chitin-induced oligomerization of chitin-independent Mg1LysM homodimers, a property that confers protection to fungal cell walls against host chitinases. A secreted LysM effector protects fungal hyphae through chitin-dependent homodimer polymerization.,Sanchez-Vallet A, Tian H, Rodriguez-Moreno L, Valkenburg DJ, Saleem-Batcha R, Wawra S, Kombrink A, Verhage L, de Jonge R, van Esse HP, Zuccaro A, Croll D, Mesters JR, Thomma BPHJ PLoS Pathog. 2020 Jun 23;16(6):e1008652. doi: 10.1371/journal.ppat.1008652. PMID:32574207[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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