Plants and animals recognize microbial invaders by detecting pathogen-associated molecular patterns (PAMPs) through pattern-recognition receptors (PRRs). This recognition plays a crucial role in plant immunity. The ne...Plants and animals recognize microbial invaders by detecting pathogen-associated molecular patterns (PAMPs) through pattern-recognition receptors (PRRs). This recognition plays a crucial role in plant immunity. The newly discovered protein in plants that responds to bacterial flagellin, i.e., flagellin-sensitive 2 (FLS2), is ubiquitously expressed and present in many plants. The association of FLS2 and BAK1, facilitated by a highly conserved epitope flg22 of flagellin, triggers such downstream immune responses as activated MAPK pathway and elevated reactive oxygen species (ROS) for bacterial defense and plant immunity. Here we study the intrinsic dynamics and conformational change of FLS2 upon the formation of the FLS2–flg22–BAK1 complex. The top intrinsic normal modes and principal structural fluctuation components are very similar, showing two bending modes and one twisting mode. The twisting mode alone, however, accounts for most of the conformational change of FLS2 induced by binding with flg22 and BAK1. This study indicates that flg22 binding suppresses FLS2 conformational fluctuation, especially on the twisting motion, thus facilitating FLS2–BAK1 interaction. A detailed analysis of this sensing mechanism may aid better design on both PRR and peptide mimetics for plant immunity.展开更多
Great efforts have been devoted to the study of photo-responsive adsorption,but its current methodology largely depends on the well-defined photochromic units and their photo-driven molecular deformation.Here,a method...Great efforts have been devoted to the study of photo-responsive adsorption,but its current methodology largely depends on the well-defined photochromic units and their photo-driven molecular deformation.Here,a methodology to fabricate nondeforming photo-responsive sorbents is successfully exploited.With C_(60)-fullerene doping in metalloporphyrin metal-organic frameworks(PCN-M,M=Fe,Co,or Ni)and intensively interacting with the metalloporphyrin sites,effective charge-transfer can be achieved over the metalloporphyrin-C_(60) architectures once excited by the light at 350 to 780 nm.The electron density distribution and the resultant adsorption activity are thus changed by excited states,which are also stable enough to meet the timescale of microscopic adsorption equilibrium.The charge-transfer over Co(II)-porphyrin-C_(60) is proved to be more efficient than the Fe(II)-and Ni(II)-porphyrin-C_(60) sites,as well as than all the metalloporphyrin sites,so the CO_(2) adsorption capacity(CAC;at 0°C and 1 bar)over the C_(60)-doped PCN-Co can be largely improved from 2.05 mmol g^(−1) in the darkness to 2.69 mmol g−1 with light,increased by 31%,in contrast to photo-irresponsive CAC over all C_(60)-undoped PCN-M sorbents and only the photo-loss CAC over C_(60).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 11704140)self-determined research funds of CCNU from the Colleges' Basic Research and Operation of MOE (Grant No. CCNU20TS004) (Y. Z.)the China Scholarship Council Fund (Grant No. 201708420039) (L. P.).
文摘Plants and animals recognize microbial invaders by detecting pathogen-associated molecular patterns (PAMPs) through pattern-recognition receptors (PRRs). This recognition plays a crucial role in plant immunity. The newly discovered protein in plants that responds to bacterial flagellin, i.e., flagellin-sensitive 2 (FLS2), is ubiquitously expressed and present in many plants. The association of FLS2 and BAK1, facilitated by a highly conserved epitope flg22 of flagellin, triggers such downstream immune responses as activated MAPK pathway and elevated reactive oxygen species (ROS) for bacterial defense and plant immunity. Here we study the intrinsic dynamics and conformational change of FLS2 upon the formation of the FLS2–flg22–BAK1 complex. The top intrinsic normal modes and principal structural fluctuation components are very similar, showing two bending modes and one twisting mode. The twisting mode alone, however, accounts for most of the conformational change of FLS2 induced by binding with flg22 and BAK1. This study indicates that flg22 binding suppresses FLS2 conformational fluctuation, especially on the twisting motion, thus facilitating FLS2–BAK1 interaction. A detailed analysis of this sensing mechanism may aid better design on both PRR and peptide mimetics for plant immunity.
基金the National Natural Science Foundation of China(22178163,22125804,and 22078155).
文摘Great efforts have been devoted to the study of photo-responsive adsorption,but its current methodology largely depends on the well-defined photochromic units and their photo-driven molecular deformation.Here,a methodology to fabricate nondeforming photo-responsive sorbents is successfully exploited.With C_(60)-fullerene doping in metalloporphyrin metal-organic frameworks(PCN-M,M=Fe,Co,or Ni)and intensively interacting with the metalloporphyrin sites,effective charge-transfer can be achieved over the metalloporphyrin-C_(60) architectures once excited by the light at 350 to 780 nm.The electron density distribution and the resultant adsorption activity are thus changed by excited states,which are also stable enough to meet the timescale of microscopic adsorption equilibrium.The charge-transfer over Co(II)-porphyrin-C_(60) is proved to be more efficient than the Fe(II)-and Ni(II)-porphyrin-C_(60) sites,as well as than all the metalloporphyrin sites,so the CO_(2) adsorption capacity(CAC;at 0°C and 1 bar)over the C_(60)-doped PCN-Co can be largely improved from 2.05 mmol g^(−1) in the darkness to 2.69 mmol g−1 with light,increased by 31%,in contrast to photo-irresponsive CAC over all C_(60)-undoped PCN-M sorbents and only the photo-loss CAC over C_(60).
