4b8v
From Proteopedia
Cladosporium fulvum LysM effector Ecp6 in complex with a beta-1,4- linked N-acetyl-D-glucosamine tetramer
Structural highlights
FunctionLYSM_PASFU Secreted effector that enables the plant pathogenic fungus to manipulate host defenses for successful infection (PubMed:18452583). Binds chitine, but not to any other glycan, including the N-linked glycan chitobiose (PubMed:20724636). Outcompetes host immune receptor for chitin binding through intrachain LysM dimerization (PubMed:18452583, PubMed:20724636). During infection, sequesters chitin oligosaccharides that are released from the cell walls of invading hyphae to prevent elicitation of host immunity (PubMed:20724636).[1] [2] Publication Abstract from PubMedWhile host immune receptors detect pathogen-associated molecular patterns to activate immunity, pathogens attempt to deregulate host immunity through secreted effectors. Fungi employ LysM effectors to prevent recognition of cell wall-derived chitin by host immune receptors, although the mechanism to compete for chitin binding remained unclear. Structural analysis of the LysM effector Ecp6 of the fungal tomato pathogen Cladosporium fulvum reveals a novel mechanism for chitin binding, mediated by intrachain LysM dimerization, leading to a chitin-binding groove that is deeply buried in the effector protein. This composite binding site involves two of the three LysMs of Ecp6 and mediates chitin binding with ultra-high (pM) affinity. Intriguingly, the remaining singular LysM domain of Ecp6 binds chitin with low micromolar affinity but can nevertheless still perturb chitin-triggered immunity. Conceivably, the perturbation by this LysM domain is not established through chitin sequestration but possibly through interference with the host immune receptor complex. DOI:http://dx.doi.org/10.7554/eLife.00790.001. Fungal effector Ecp6 outcompetes host immune receptor for chitin binding through intrachain LysM dimerization.,Sanchez-Vallet A, Saleem-Batcha R, Kombrink A, Hansen G, Valkenburg DJ, Thomma BP, Mesters JR Elife. 2013 Jul 2;2:e00790. doi: 10.7554/eLife.00790. Print 2013. PMID:23840930[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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