Control of type III-mediated virulence by a key bacterial signal (MALONE_J17DTP1)

细菌III型注射体T3 I是一种针状结构，可将效应物和毒素直接递送到宿主细胞中。T3 I在许多细菌的致病性和宿主感染中起着至关重要的作用，包括主要的人类和植物病原体铜绿假单胞菌（P. aeruginosa）和铜绿假单胞菌（P. eruginae）。我们最近发现，T3 I的一个关键组成部分;输出ATP酶复合物，特异性地结合信号分子环二GMP（cdG），这是许多细菌病原体中与毒力控制相关的细菌行为的关键调节剂。确定T3 I和cdG之间的关系是理解细菌感染期间T3 I调节的关键。在这个项目中，我们将结合遗传学，生物化学和结构生物学来定义cdG结合如何控制铜绿假单胞菌和铜绿假单胞菌的T3 I。学生将在两个物种中构建特异性cdG结合突变体，并将其用于毒力和效应蛋白输出。这些实验将得到纯化的ATP酶蛋白的深入生化分析的支持。新出现的cdG-ATPase控制模型将通过cryo-EM和X-射线晶体学的结构表征来完善。

The bacterial Type III Injectisome T3I is a needle-like structure that delivers effectors and toxins directly into host cells. The T3I plays a crucial role in pathogenicity and host infection in many bacteria, including the major human and plant pathogens P. aeruginosa and P. syringae. We recently showed that a crucial component of the T3I; the export ATPase complex, binds specifically to the signalling molecule cyclic-di-GMP (cdG), a key regulator of bacterial behaviour associated with virulence control in many bacterial pathogens.Defining the relationship between the T3I and cdG is key to understanding T3I regulation during bacterial infections.In this project, we will use a combination of genetics, biochemistry and structural biology to define how cdG-binding controls the T3Is of P. aeruginosa and P. syringae. The student will construct specific cdG-binding mutants in both species, and characterise them for virulence and effector protein export. These experiments will be supported by in-depth biochemical analysis of purified ATPase proteins. The emerging model for cdG-ATPase control will be refined by structural characterisation by cryo-EM and X-ray crystallography.