Two flagellar stators and their roles in motility and virulence in Pseudomonas syringae pv. tabaci 6605
Two flagellar stators and their roles in motility and virulence in Pseudomonas syringae pv. tabaci 6605
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DOI：
10.1007/s00438-010-0594-8
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发表时间：
2011-02-01
影响因子：
3.1
通讯作者：
Ichinose, Yuki
中科院分区：
文献类型：
--
作者：
Kanda, Eiko;Tatsuta, Takafumi;Ichinose, Yuki
鞭毛基体周围的马达蛋白由两种细胞膜蛋白MOTA和MOTB组成，作为一个复合体发挥作用，作为定子来产生驱动旋转的扭矩。对几个丁香假单胞菌致病变种的基因组分析表明，存在两套编码运动蛋白的基因：motAB和motCD。推导的MotA/B和MotC/D氨基酸序列分别与大肠杆菌H+驱动的定子和溶藻弧菌的Na+驱动的定子同源。而紫丁香对虾的游动能力较弱。Tabaci(PTA)6605可被原载体羰基氰化物间氯苯肼抑制，但不能被定子特异性抑制剂非那米所抑制。为了确定编码运动所需定子蛋白的基因，产生了匕首motAB、匕首motCD和匕首motABCD突变体。A匕首motCD突变体显著减少，a匕首motABCD突变体完全取消游泳运动，而a匕首motAB突变体保留了一定程度的这些能力。A匕首motCD和a dagger motABCD突变体不产生N-酰基高丝氨酸内酯(AHL)，这是该病原菌中的群体感应分子，并显著降低了在寄主烟草叶片中致病的能力，正如我们以前在a dagger flic突变体中观察到的那样。这些结果有力地表明，PTA 6605的两个定子对都是质子依赖的，MotCD不仅对鞭毛的运动很重要，而且对AHLS的产生和寄主植物的致病能力也是重要的。
The motor proteins around the flagellar basal body consist of two cytoplasmic membrane proteins, MotA and MotB, and function as a complex that acts as the stator to generate the torque that drives rotation. Genome analysis of several Pseudomonas syringae pathovars revealed that there are two sets of genes encoding motor proteins: motAB and motCD. Deduced amino acid sequences for MotA/B and MotC/D showed homologies to the H+-driven stator from Escherichia coli and Na+-driven stator from Vibrio alginolyticus, respectively. However, the swimming motility of P. syringae pv. tabaci (Pta) 6605 was inhibited by the protonophore carbonyl cyanide m-chlorophenylhydrazone but not by the sodium stator-specific inhibitor phenamil. To identify a gene encoding the stator protein required for motility, a dagger motAB, a dagger motCD, and a dagger motABCD mutants were generated. The a dagger motCD mutant had remarkably reduced and the a dagger motABCD mutant completely abolished swimming motilities, whereas the a dagger motAB mutant retained some degree of these abilities. The a dagger motCD and a dagger motABCD mutants did not produce N-acyl-homoserine lactones (AHLs), quorum-sensing molecules in this pathogen, and remarkably reduced the ability to cause disease in host tobacco leaves, as we previously observed in the a dagger fliC mutant strain. These results strongly indicate that both stator pairs in Pta 6605 are proton-dependent and that MotCD is important for not only flagellar motility but also for production of AHLs and the ability to cause disease in host plants.