Poster
Wei-Lin Wan (he/him/his)
Dr.
Natl Univ of Singapore
Singapore, Singapore
Gijeong Kim
Institute of Plant and Microbial Biology, University of Zurich
Zurich, Zurich, Switzerland
Nayun Kim
Korea Advanced Institute of Science and Technology
Daejeon, Ch'ungch'ong-namdo, Republic of Korea
Yi Yun Tan
National University of Singapore
Singapore, Singapore
Nuri Charoennit
National University of Singapore
Singapore, Singapore
Rachelle R. Q. Lee
National University of Singapore
Singapore, Singapore
Yin Yin Liew
National University of Singapore
Singapore, Singapore
Shen Kai Ng
National University of Singapore
Singapore, Singapore
Yizhong Zhang
National University of Singapore
Singapore, Singapore
Ji-Joon Song
Korea Advanced Institute of Science and Technology
Daejeon, Ch'ungch'ong-namdo, Republic of Korea
Eunyoung Chae
University of Oxford
Oxford, England, United Kingdom
Genetic incompatibility occurs when a mismatched pair of plant immune components mounts autoimmune responses in hybrids. Highly diversified NLR receptors are main culprits of the genetic conflict, recognizing host proteins from different origin as immune trigger. Here, we report the molecular mechanism underlying a DANGEROUS MIX (DM) autoimmunity, comprising DM2h/RPP1 NLR and its incompatible partner DM3, an alpha/beta hydrolase. Cryo-electron microscopy reveals the oligomeric nature of two natural DM3 variants in a trimer of dimer configuration. The polymorphism triggering autoimmunity is located at the dimer interface, resulting in drastic structural differences such that dimerizing helix and loop reinforcing the interface is lost and disordered. Structure-function analysis shows that integrity of the dimer interface, but neither maintenance of hexamer nor its enzymatic activity, is the key factor contributing to autoimmunity. Our finding pinpoints checkpoints embedded in the oligomeric configuration of a host enzyme that controls the switching mechanism of NLR activity.