title: Molecular Mechanism for Fungal Cell Wall Recognition by Rice Chitin Receptor OsCEBiP.
abstract: Chitin is the major component of fungal cell wall and serves as a molecular pattern that can be recognized by the receptor OsCEBiP in rice, a lysine motif (LysM) receptor-like protein (RLP), to trigger immune responses. The molecular mechanisms underlying chitin recognition remain elusive. Here we report the crystal structures of the ectodomain of OsCEBiP (OsCEBiP-ECD) in free and chitin-bound forms. The structures reveal that OsCEBiP-ECD contains three tandem LysMs followed by a novel structure fold of cysteine-rich domain. The structures showed that chitin binding induces no striking conformational changes in OsCEBiP. Structural comparison among N-acetylglucosamine (NAG) oligomer-bound LysMs revealed a highly conserved recognition mechanism, which is expected to facilitate study of other LysM-containing proteins for their NAG binding. Modeling study showed that chitin induces OsCEBiP homodimerization in a "sliding mode". Our data provide insights into rice chitin receptor-mediated immunity triggered by fungal cell wall.
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Simiao
authors.initials: S
authors.lastname: Liu
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Jizong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Zhifu
authors.initials: Z
authors.lastname: Han
authors.affiliation: Institute for Mathematical Sciences, Renmin University of China, Beijing 100872, China.
authors.forename: Xinqi
authors.initials: X
authors.lastname: Gong
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Heqiao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China. Electronic address: chaijj@tsinghua.edu.cn.
authors.forename: Jijie
authors.initials: J
authors.lastname: Chai
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D002686:Chitin / Q000737:chemistry / Q000378:metabolism*; D005658:Fungi / Q000737:chemistry; D062105:Molecular Docking Simulation; D012275:Oryza / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D011956:Receptors, Cell Surface; D002686:Chitin; D000117:Acetylglucosamine