当前位置： SCI文献检索 > JOURNAL OF BACTERIOLOGY期刊下所有文献 > In Situ Structure of the Vibrio Polar Flagellum Reveals a Distinct Outer Membrane Complex and Its Specific Interaction with the Stator.

In Situ Structure of the Vibrio Polar Flagellum Reveals a Distinct Outer Membrane Complex and Its Specific Interaction with the Stator.

Abstract：

:The bacterial flagellum is a biological nanomachine that rotates to allow bacteria to swim. For flagellar rotation, torque is generated by interactions between a rotor and a stator. The stator, which is composed of MotA and MotB subunit proteins in the membrane, is thought to bind to the peptidoglycan (PG) layer, which anchors the stator around the rotor. Detailed information on the stator and its interactions with the rotor remains unclear. Here, we deployed cryo-electron tomography and genetic analysis to characterize in situ structure of the bacterial flagellar motor in Vibrio alginolyticus, which is best known for its polar sheathed flagellum and high-speed rotation. We determined in situ structure of the motor at unprecedented resolution and revealed the unique protein-protein interactions among Vibrio-specific features, namely the H ring and T ring. Specifically, the H ring is composed of 26 copies of FlgT and FlgO, and the T ring consists of 26 copies of a MotX-MotY heterodimer. We revealed for the first time a specific interaction between the T ring and the stator PomB subunit, providing direct evidence that the stator unit undergoes a large conformational change from a compact form to an extended form. The T ring facilitates the recruitment of the extended stator units for the high-speed motility in Vibrio species.IMPORTANCE The torque of flagellar rotation is generated by interactions between a rotor and a stator; however, detailed structural information is lacking. Here, we utilized cryo-electron tomography and advanced imaging analysis to obtain a high-resolution in situ flagellar basal body structure in Vibrio alginolyticus, which is a Gram-negative marine bacterium. Our high-resolution motor structure not only revealed detailed protein-protein interactions among unique Vibrio-specific features, the T ring and H ring, but also provided the first structural evidence that the T ring interacts directly with the periplasmic domain of the stator. Docking atomic structures of key components into the in situ motor map allowed us to visualize the pseudoatomic architecture of the polar sheathed flagellum in Vibrio spp. and provides novel insight into its assembly and function.

journal_name

J Bacteriol

journal_title

Journal of bacteriology

authors

Zhu S,Nishikino T,Takekawa N,Terashima H,Kojima S,Imada K,Homma M,Liu J

doi

10.1128/JB.00592-19

subject

Has Abstract

pub_date

2020-01-29 00:00:00

issue

eissn

0021-9193

issn

1098-5530

pii

JB.00592-19

journal_volume

202

pub_type

杂志文章

在线工具

In Situ Structure of the Vibrio Polar Flagellum Reveals a Distinct Outer Membrane Complex and Its Specific Interaction with the Stator.