A positive charge region of Salmonella FliI is required for ATPase formation and efficient flagellar protein export.
A positive charge region of Salmonella FliI is required for ATPase formation and efficient flagellar protein export.
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DOI：
10.1038/s42003-021-01980-y
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发表时间：
2021-04-12
影响因子：
5.9
通讯作者：
Minamino T
中科院分区：
文献类型：
--
作者：
Kinoshita M;Namba K;Minamino T
在肠沙门氏菌中，FliH2FliI复合体被认为是将鞭毛亚基蛋白从细胞质引导到鞭毛组装的跨膜出口门复合体。FliI还形成一个同型六聚体来水解ATP，从而激活出口门复合体，成为一个活跃的蛋白质转运体。然而，这种激活是如何发生的尚不清楚。本文报道了由fli的Arg-26、Arg-27、Arg-33、Arg-76和Arg-93组成的带正电簇在鞭毛蛋白输出中的作用。我们发现Arg-33和Arg-76参与了FliI环的形成，并且FliI （R26A/R27A/R33A/R76A/R93A）突变体需要FliH的存在才能充分发挥其输出功能。我们观察到FlhB的功能获得突变增加了底物进入出口门复合体的概率，从而恢复了∆fliH fliI（R26A/R27A/R33A/R76A/R93A）突变体的出口功能。我们认为FliI的正电荷簇不仅负责良好调节的六聚体组装，而且还负责底物进入gate复合物。Kinoshita， Namba和Minamino表明，在沙门氏菌FliI中，一簇带正电的精氨酸是形成FliI同型六聚体atp酶所必需的。通过功能损失和功能获得实验，他们证明六聚体组装也负责鞭毛组装过程中鞭毛蛋白的有效输出。
The FliH2FliI complex is thought to pilot flagellar subunit proteins from the cytoplasm to the transmembrane export gate complex for flagellar assembly in Salmonella enterica. FliI also forms a homo-hexamer to hydrolyze ATP, thereby activating the export gate complex to become an active protein transporter. However, it remains unknown how this activation occurs. Here we report the role of a positively charged cluster formed by Arg-26, Arg-27, Arg-33, Arg-76 and Arg-93 of FliI in flagellar protein export. We show that Arg-33 and Arg-76 are involved in FliI ring formation and that the fliI(R26A/R27A/R33A/R76A/R93A) mutant requires the presence of FliH to fully exert its export function. We observed that gain-of-function mutations in FlhB increased the probability of substrate entry into the export gate complex, thereby restoring the export function of the ∆fliH fliI(R26A/R27A/R33A/R76A/R93A) mutant. We suggest that the positive charge cluster of FliI is responsible not only for well-regulated hexamer assembly but also for substrate entry into the gate complex. Kinoshita, Namba and Minamino show that a cluster of positively-charged arginines in the Salmonella FliI is necessary for formation of the FliI homo-hexamer ATPase. Through loss- and gain-of-function experiments, they demonstrate that hexamer assembly is also responsible for efficient export of flagellar proteins during flagellar assembly.
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影响因子：
9.8
作者：
Fukumura T;Makino F;Dietsche T;Kinoshita M;Kato T;Wagner S;Namba K;Imada K;Minamino T
通讯作者：
Minamino T
影响因子：
4.6
作者：
Bai F;Morimoto YV;Yoshimura SD;Hara N;Kami-Ike N;Namba K;Minamino T
通讯作者：
Minamino T
影响因子：
3.2
作者：
Minamino, Tohru;Shimada, Masafumi;Namba, Keiichi
通讯作者：
Namba, Keiichi
影响因子：
16.6
作者：
Kuhlen, Lucas;Johnson, Steven;Lea, Susan M.
通讯作者：
Lea, Susan M.
DOI：
10.1016/j.bbrc.2009.08.004
发表时间：
2009-10-16
影响因子：
3.1
作者：
Kazetani, Ken-ichi;Minamino, Tohru;Namba, Keiichi
通讯作者：
Namba, Keiichi