Genetic and molecular evidence that the Pseudomonas syringae type III effector protein AvrRpt2 is a cysteine protease
Genetic and molecular evidence that the Pseudomonas syringae type III effector protein AvrRpt2 is a cysteine protease
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DOI：
10.1046/j.1365-2958.2003.03666.x
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发表时间：
2003-09-01
影响因子：
3.6
通讯作者：
Staskawicz, BJ
中科院分区：
文献类型：
--
作者：
Axtell, MJ;Chisholm, ST;Staskawicz, BJ
在感染期间递送至植物细胞后，假单胞菌效应蛋白AvrRpt 2经历蛋白水解加工，增强病原体毒力并引起拟南芥RIN 4蛋白的消除。采用结构预测方法研究AvrRpt 2可能的生化功能。二级结构预测算法的结果表明AvrRpt 2的功能性C-末端部分是半胱氨酸蛋白酶。预测的催化残基内的AvrRpt 2的这一部分的突变废除在植物加工，消除拟南芥RIN 4，并能够触发RPS 2特异性抗性反应。这些数据表明，AvrRpt 2最有可能是一种序列趋异的半胱氨酸蛋白酶，其活性是在感染期间消除RIN 4所必需的。
Upon delivery to the plant cell during infection, the Pseudomonas syringae effector protein AvrRpt2 undergoes proteolytic processing, enhances pathogen virulence and causes the elimination of the Arabidopsis RIN4 protein. A structure-prediction method was employed in order to investigate possible biochemical functions of AvrRpt2. Results of a secondary structure prediction algorithm suggest that the functional C-terminal portion of AvrRpt2 is a cysteine protease. Mutation of predicted catalytic residues within this portion of AvrRpt2 abolished in planta processing, elimination of Arabidopsis RIN4, and the ability to trigger an RPS2-specific resistance response. These data indicate that AvrRpt2 is most likely a sequence divergent cysteine protease whose activity is required for elimination of RIN4 during infection.