Kim Young Jin, Lin Nai Chun, Martin Gregory B
Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA.
Cell. 2002 May 31;109(5):589-98. doi: 10.1016/s0092-8674(02)00743-2.
The Pto serine/threonine kinase of tomato confers resistance to speck disease by recognizing strains of Pseudomonas syringae that express the protein AvrPto. Pto and AvrPto physically interact, and this interaction is required for activation of host resistance. We identified a second Pseudomonas protein, AvrPtoB, that interacts specifically with Pto and is widely distributed among plant pathogens. AvrPtoB is delivered into the plant cell by the bacterial type III secretion system, and it elicits Pto-specific defenses. AvrPtoB has little overall sequence similarity with AvrPto. However, AvrPto amino acids, which are required for interaction with Pto, are present in AvrPtoB and required for its interaction with Pto. Thus, two distinct bacterial effectors activate plant immunity by interacting with the same host protein kinase through a similar structural mechanism.
番茄的Pto丝氨酸/苏氨酸激酶通过识别表达AvrPto蛋白的丁香假单胞菌菌株来赋予对斑点病的抗性。Pto和AvrPto发生物理相互作用，这种相互作用是激活宿主抗性所必需的。我们鉴定出了第二种假单胞菌蛋白AvrPtoB，它与Pto特异性相互作用，并且在植物病原体中广泛分布。AvrPtoB通过细菌III型分泌系统被递送到植物细胞中，并引发Pto特异性防御反应。AvrPtoB与AvrPto总体序列相似性较低。然而，与Pto相互作用所需的AvrPto氨基酸存在于AvrPtoB中，并且是其与Pto相互作用所必需的。因此，两种不同的细菌效应子通过类似的结构机制与同一宿主蛋白激酶相互作用来激活植物免疫。
