Analysis of structure and function of RPS4 and RRS1 proteins

研究发现，拟南芥RRS1和RPS4都是抗性高炭疽菌、茄枯菌和丁香假单胞菌的必需基因。表达avrRps4的番茄菌株DC3000。这两个相邻的R基因串联或单独赋予对三种具有非常不同感染策略和毒力机制的不同病原体的抗性。比较了20个生态型的RPS4等位基因的氨基酸序列，发现它们的蛋白质序列高度相似。相反，通过比较20个生态型，我们发现RRS1的LRR结构域和c端区域存在一些差异。受体型R蛋白的自然变异通常发生在其LRR结构域，通常发生在溶剂暴露的β-链/β-转结构上。LRR结构域的强大选择压力表明，这是直接与快速进化的病原体决定因子结合的结构域。我们在RPS4和RRS1中引入了一些氨基酸的变化，揭示了RPS4和RRS1蛋白的结构和功能。

We found that both Arabidopsis RRS1 and RPS4 are required for resistance to Colletotrichum higginsianum, Ralstonia solanacearum and Pseudomonas syringae pv. tomato strain DC3000 expressing avrRps4.These two adjacent R genes confer resistance, in tandem or individually, to three distinct pathogens with very different infection strategies and virulence mechanisms. The comparison of amino acid sequences of the RPS4 alleles from twenty ecotypes revealed the protein sequences were highly similar. On the contrary, we found several variations in the LRR domain and C-terminal region of RRS1 by comparing twenty ecotypes. Natural variation in receptor-type R proteins often occurs in their LRR domain, typically at the solvent exposedβ-strand/β-turn structure. The strong selection pressure at the LRR domain suggests that this is the domain directly binds to the pathogen determinants that are evolving fast. We introduced some amino acid changes into RPS4 and RRS1, and we revealed the structure and function of RPS4 and RRS1 proteins.