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

 -  Structure, 24(7), p.1192-1200, 2016 .
<br/><br/> 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. © 2016 Elsevier Ltd 
<br/><br/><label>Subjects--Topical Terms: </label><br/>PLANT INNATE IMMUNITY<br/>PERCEPTION<br/>ARABIDOPSIS<br/>PROTEINS<br/>KINASE<br/>CERK1<br/>MOTIF<br/>CEBIP<br/>PEPTIDOGLYCAN<br/>DIMERIZATION