Assembly dynamics and the roles of FliI ATPase of the bacterial flagellar export apparatus.
Assembly dynamics and the roles of FliI ATPase of the bacterial flagellar export apparatus.
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DOI：
10.1038/srep06528
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发表时间：
2014-10-06
影响因子：
4.6
通讯作者：
Minamino T
中科院分区：
文献类型：
--
作者：
Bai F;Morimoto YV;Yoshimura SD;Hara N;Kami-Ike N;Namba K;Minamino T
为了构建细菌鞭毛，FliI ATPase在细胞质中形成FliH2-FliI复合体，并通过FliH与C环蛋白flin的相互作用定位于鞭毛基体(FBB)。FliI还组装成同源六聚体，以促进出口底物最初进入出口门。FliH与出口GATE蛋白FlhA的相互作用是FliI6环稳定锚定到GATE所必需的。在这里，我们报道了FliI-YFP的化学计量和组装动力学的单分子精密荧光显微镜。超过6个FliI-YFP分子通过FliH与Flin和FlhA相互作用与FBB结合。FliI-YFP分子在FBB定域分子和自由扩散分子之间每分钟交换数次。FliI的催化突变既不影响与FBB相关的FliI-YFP的数量，也不影响FliI-YFP的周转率，表明FliI的ATP水解并不驱动FliI在鞭毛组装过程中的组装-拆解周期。我们认为FliH2 FliI复合体和FliI6环分别作为动态底物载体和静态底物载入器。
For construction of the bacterial flagellum, FliI ATPase forms the FliH2-FliI complex in the cytoplasm and localizes to the flagellar basal body (FBB) through the interaction of FliH with a C ring protein, FliN. FliI also assembles into a homo-hexamer to promote initial entry of export substrates into the export gate. The interaction of FliH with an export gate protein, FlhA, is required for stable anchoring of the FliI6 ring to the gate. Here we report the stoichiometry and assembly dynamics of FliI-YFP by fluorescence microscopy with single molecule precision. More than six FliI-YFP molecules were associated with the FBB through interactions of FliH with FliN and FlhA. Single FliI-YFP molecule exchanges between the FBB-localized and free-diffusing ones were observed several times per minute. Neither the number of FliI-YFP associated with the FBB nor FliI-YFP turnover rate were affected by catalytic mutations in FliI, indicating that ATP hydrolysis by FliI does not drive the assembly-disassembly cycle of FliI during flagellar assembly. We propose that the FliH2FliI complex and FliI6 ring function as a dynamic substrate carrier and a static substrate loader, respectively.
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影响因子：
3.2
作者：
Ibuki, Tatsuya;Uchida, Yumiko;Minamino, Tohru
通讯作者：
Minamino, Tohru
影响因子：
2.9
作者：
McMurry, Jonathan L.;Murphy, James W.;Gonzalez-Pedrajo, Bertha
通讯作者：
Gonzalez-Pedrajo, Bertha
影响因子：
3.7
作者：
Kishikawa J;Ibuki T;Nakamura S;Nakanishi A;Minamino T;Miyata T;Namba K;Konno H;Ueno H;Imada K;Yokoyama K
通讯作者：
Yokoyama K
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
DOI：
10.1073/pnas.0806338105
发表时间：
2008-10-07
影响因子：
11.1
作者：
Leake, Mark C.;Greene, Nicholas P.;Berks, Ben C.
通讯作者：
Berks, Ben C.