水稻几丁质受体OsCEBiP的真菌细胞壁识别分子机制  

Molecular Mechanism for Fungal Cell Wall Recognition by Rice Chitin Receptor OsCEBiP

作　　者：Simiao Liu Jizong Wang Zhifu Han Xinqi Gong Heqiao Zhang 柴继杰[2] 

机构地区：[1]不详 [2]清华大学生命科学学院

出　　处：《科学新闻》2017年第4期181-181,共1页Science News

基　　金：国家自然科学基金国际合作与交流项目(31420103906);科技部项目(2015CB910200)的支持

摘　　要：几丁质是真菌细胞壁的主要成分，可被水稻OsCEBiP受体识别引发免疫反应。水稻OsCEBiP受体属于赖氯酸基序（LysM）受体样蛋白（RLP）。然而，几丁质的分子识别机制仍然不清楚。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.

关 键 词：分子机制 几丁质 受体 识别 水稻 细胞 真菌 免疫反应 

分 类 号：Q516[生物学—生物化学]