4ebz
From Proteopedia
Crystal structure of the ectodomain of a receptor like kinase
Structural highlights
FunctionCERK1_ARATH Lysin motif (LysM) receptor kinase that functions as a cell surface receptor in chitin elicitor (chitooligosaccharides) signaling leading to innate immunity toward both biotic and abiotic stresses (e.g. tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection). Recognizes microbe-derived N-acetylglucosamine (NAG)-containing ligands. Involved in the resistance to pathogenic fungi Alternaria brassicicola and Erysiphe cichoracearum, probably by sensing microbe-associated molecular patterns (MAMP) and pathogen-associated molecular patterns (PAMP). Plays an essential role in detecting peptidoglycans (e.g. PGNs) and restricting bacterial growth. Target of the bacterial type III effector E3-ligase protein hopAB2/avrPtoB of Pseudomonas syringae pv. tomato DC3000 that mediates ubiquitination and subsequent proteolysis, thus blocking all defense responses by suppressing PAMP-triggered immunity (PTI).[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedPattern recognition receptors confer plant resistance to pathogen infection by recognizing the conserved pathogen-associated molecular patterns. The cell surface receptor chitin elicitor receptor kinase 1 of Arabidopsis (AtCERK1) directly binds chitin through its lysine motif (LysM)-containing ectodomain (AtCERK1-ECD) to activate immune responses. The crystal structure that we solved of an AtCERK1-ECD complexed with a chitin pentamer reveals that their interaction is primarily mediated by a LysM and three chitin residues. By acting as a bivalent ligand, a chitin octamer induces AtCERK1-ECD dimerization that is inhibited by shorter chitin oligomers. A mutation attenuating chitin-induced AtCERK1-ECD dimerization or formation of nonproductive AtCERK1 dimer by overexpression of AtCERK1-ECD compromises AtCERK1-mediated signaling in plant cells. Together, our data support the notion that chitin-induced AtCERK1 dimerization is critical for its activation. Chitin-induced dimerization activates a plant immune receptor.,Liu T, Liu Z, Song C, Hu Y, Han Z, She J, Fan F, Wang J, Jin C, Chang J, Zhou JM, Chai J Science. 2012 Jun 1;336(6085):1160-4. PMID:22654057[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. Loading citation details.. Citations No citations found References
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Categories: Arabidopsis thaliana | Large Structures | Chai J | Han Z | Liu T | She J | Wang J