FliL ring enhances the function of periplasmic flagella.
FliL ring enhances the function of periplasmic flagella.
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DOI：
10.1073/pnas.2117245119
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发表时间：
2022-03-15
影响因子：
11.1
通讯作者：
Liu J
中科院分区：
文献类型：
--
作者：
Guo S;Xu H;Chang Y;Motaleb MA;Liu J
鞭毛如何感知复杂的环境和控制细菌的运动仍然是令人着迷的问题。在这里，我们部署冷冻电子断层扫描，以确定在野生型和突变型细胞的伯氏疏螺旋体的鞭毛电机的原位结构，揭示了三个鞭毛蛋白（FliL，MotA和MotB）形成一个独特的超分子复合物在原位。重要的是，FliL不仅通过在定子复合体MotA/MotB周围以其延伸的活性构象形成环来增强电机功能，而且还促进定子复合体在电机周围的组装。我们的原位数据提供了对FliL定子超分子复合物的合作重塑如何帮助调节集体离子通量并建立鞭毛马达的最佳功能以引导细菌在各种环境中的运动性的见解。细菌鞭毛马达是旋转机器，可以在各种流体和表面环境中提供动力，包括宿主内。定子复合体MotA/MotB的激活是产生转矩和电机旋转所必需的。在激活期间，预期定子复合物经历广泛的构象变化以允许离子流过其跨膜通道以产生扭矩。然而，定子激活的详细机制仍然知之甚少。在这里，我们使用莱姆病致病螺旋体伯氏疏螺旋体作为模型系统，揭示定子复合物及其与FliL环的相互作用，使用冷冻电子断层扫描和鞭毛马达的亚断层扫描平均值从野生型，ΔmotB，ΔfliL和ΔfliLmotAB突变体。在定子单元募集到马达时，FliL从部分环寡聚成完整环，其包裹MotB周质接头并使定子复合物稳定在延伸的活性构象中，从而使离子的连续流入产生更高的扭矩。此外，我们提供的证据表明，FliL可以调解电机周围的定子复合体的组装，从而调节定子和电机功能。鉴于FliL和定子复合物在有鞭毛的细菌中普遍存在，这些机制可以被各种细菌利用来响应于变化的环境条件来调节扭矩和运动性。
How flagella sense complex environments and control bacterial motility remain fascinating questions. Here, we deploy cryo-electron tomography to determine in situ structures of the flagellar motor in wild-type and mutant cells of Borrelia burgdorferi, revealing that three flagellar proteins (FliL, MotA, and MotB) form a unique supramolecular complex in situ. Importantly, FliL not only enhances motor function by forming a ring around the stator complex MotA/MotB in its extended, active conformation but also facilitates assembly of the stator complex around the motor. Our in situ data provide insights into how cooperative remodeling of the FliL–stator supramolecular complex helps regulate the collective ion flux and establishes the optimal function of the flagellar motor to guide bacterial motility in various environments. Bacterial flagellar motors are rotary machines that can power motility in various fluid and surface environments, including within hosts. Activation of the stator complex MotA/MotB is required for torque generation and motor rotation. During activation, the stator complex is expected to undergo an extensive conformational change to allow ions to flow through its transmembrane channels to generate torque. However, the detailed mechanism underlying stator activation remains poorly understood. Here, we use the Lyme disease–causing spirochete Borrelia burgdorferi as the model system to reveal the stator complex and its interaction with the FliL ring, using cryo-electron tomography and subtomogram averaging of flagellar motors from wild-type, ΔmotB, ΔfliL, and ΔfliLmotAB mutants. Upon recruitment of stator units to the motor, FliL oligomerizes from a partial ring into a full ring, which wraps around the MotB periplasmic linkers and stabilizes the stator complex in an extended, active conformation, thus enabling a continuous influx of ions to generate higher torque. Furthermore, we provide evidence that FliL can mediate the assembly of stator complexes around the motor, thereby regulating stator and motor function. Given that FliL and the stator complex are ubiquitous in flagellated bacteria, these mechanisms may be utilized by various bacteria to modulate torque and motility in response to changing environmental conditions.
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影响因子：
7.7
作者：
Carroll BL;Nishikino T;Guo W;Zhu S;Kojima S;Homma M;Liu J
通讯作者：
Liu J
影响因子：
64.8
作者：
Jumper J;Evans R;Pritzel A;Green T;Figurnov M;Ronneberger O;Tunyasuvunakool K;Bates R;Žídek A;Potapenko A;Bridgland A;Meyer C;Kohl SAA;Ballard AJ;Cowie A;Romera-Paredes B;Nikolov S;Jain R;Adler J;Back T;Petersen S;Reiman D;Clancy E;Zielinski M;Steinegger M;Pacholska M;Berghammer T;Bodenstein S;Silver D;Vinyals O;Senior AW;Kavukcuoglu K;Kohli P;Hassabis D
通讯作者：
Hassabis D
驱动细菌鞭毛旋转的定子配合物的结构。
影响因子：
28.3
作者：
Deme JC;Johnson S;Vickery O;Aron A;Monkhouse H;Griffiths T;James RH;Berks BC;Coulton JW;Stansfeld PJ;Lea SM
通讯作者：
Lea SM
影响因子：
14.8
作者：
Kelley LA;Mezulis S;Yates CM;Wass MN;Sternberg MJ
通讯作者：
Sternberg MJ
影响因子：
3
作者：
Agulleiro, Jose-Ignacio;Fernandez, Jose-Jesus
通讯作者：
Fernandez, Jose-Jesus