GFP Fusion to the N-Terminus of MotB Affects the Proton Channel Activity of the Bacterial Flagellar Motor in Salmonella.
GFP Fusion to the N-Terminus of MotB Affects the Proton Channel Activity of the Bacterial Flagellar Motor in Salmonella.
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DOI：
10.3390/biom10091255
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发表时间：
2020-08-29
期刊：
影响因子：
5.5
通讯作者：
Minamino T
中科院分区：
文献类型：
--
作者：
Morimoto YV;Namba K;Minamino T
细菌鞭毛马达将流经MOTA/MOTB复合体的质子能量转化为马达旋转所需的机械功。旋转力是由定子蛋白MoTA和转子蛋白FliG之间的静电相互作用产生的。MOTA的Arg-90和Glu-98分别与FliG的Asp-289和Arg-281相互作用。野生型MoTA/MOTB复合体表达水平的提高抑制了GFP-MOTB flG(R281V)突变体的运动，但不抑制fliG(R281V)突变体的运动，这表明在存在fliG(R281V)突变的情况下，MoTA/GFP-MOTB复合体不能与野生型MoTA/MOTB一起工作。然而，原因仍不清楚。在这里，我们研究了GFP融合到MOTB的N端对MOTA/MOTB功能的影响。野生型MOTA/MOTB的过表达显著降低了GFP-MOTB flG(R281V)突变体的生长速度。MoTA/GFP-MOTB复合体的过度表达导致其质子通道过度质子泄漏，从而抑制细胞生长。这些结果表明，MOTB N末端的GFP标签影响通过MOTA/MOTB质子通道的质子转运。因此，我们认为MOTB的N端细胞质尾巴将质子通道的门控与负责扭矩产生的MoTA-FliG相互作用耦合起来。
The bacterial flagellar motor converts the energy of proton flow through the MotA/MotB complex into mechanical works required for motor rotation. The rotational force is generated by electrostatic interactions between the stator protein MotA and the rotor protein FliG. The Arg-90 and Glu-98 from MotA interact with Asp-289 and Arg-281 of FliG, respectively. An increase in the expression level of the wild-type MotA/MotB complex inhibits motility of the gfp-motB fliG(R281V) mutant but not the fliG(R281V) mutant, suggesting that the MotA/GFP-MotB complex cannot work together with wild-type MotA/MotB in the presence of the fliG(R281V) mutation. However, it remains unknown why. Here, we investigated the effect of the GFP fusion to MotB at its N-terminus on the MotA/MotB function. Over-expression of wild-type MotA/MotB significantly reduced the growth rate of the gfp-motB fliG(R281V) mutant. The over-expression of the MotA/GFP-MotB complex caused an excessive proton leakage through its proton channel, thereby inhibiting cell growth. These results suggest that the GFP tag on the MotB N-terminus affects well-regulated proton translocation through the MotA/MotB proton channel. Therefore, we propose that the N-terminal cytoplasmic tail of MotB couples the gating of the proton channel with the MotA–FliG interaction responsible for torque generation.
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DOI：
10.2142/biophysics.9.173
发表时间：
2013
期刊：
Biophysics (Nagoya-shi, Japan)
影响因子：
--
作者：
Castillo DJ;Nakamura S;Morimoto YV;Che YS;Kami-Ike N;Kudo S;Minamino T;Namba K
通讯作者：
Namba K
影响因子：
3.2
作者：
Che, Yong-Suk;Nakamura, Shuichi;Minamino, Tohru
通讯作者：
Minamino, Tohru
影响因子：
2.9
作者：
Braun, TF;Al-Mawsawi, LQ;Blair, DF
通讯作者：
Blair, DF
影响因子：
4.6
作者：
Heo M;Nord AL;Chamousset D;van Rijn E;Beaumont HJE;Pedaci F
通讯作者：
Pedaci F
影响因子：
5.7
作者：
Kojima, Seiji;Takao, Masato;Imada, Katsumi
通讯作者：
Imada, Katsumi