7SGP

Crystal structure of periplasmic domain of Helicobacter pylori FliL (residues 81 to 183) (crystal form C)

7SGP の概要

• エントリーDOI: 10.2210/pdb7sgp/pdb
• 分子名称: Flagellar protein FliL (2 entities in total)
• 機能のキーワード: flagellar motor, flil, motor protein
• 由来する生物種: Helicobacter pylori (Campylobacter pylori)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 12684.60

構造登録者

Chan, K.L.,Peterson, B.,Khan, M.F.,Roujeinikova, A. (登録日: 2021-10-06, 公開日: 2022-03-23, 最終更新日: 2024-05-22)

主引用文献

Tachiyama, S.,Chan, K.L.,Liu, X.,Hathroubi, S.,Peterson, B.,Khan, M.F.,Ottemann, K.M.,Liu, J.,Roujeinikova, A.
The flagellar motor protein FliL forms a scaffold of circumferentially positioned rings required for stator activation.
Proc.Natl.Acad.Sci.USA, 119:-, 2022

PubMed Abstract: The flagellar motor stator is an ion channel nanomachine that assembles as a ring of the MotAMotB units at the flagellar base. The role of accessory proteins required for stator assembly and activation remains largely enigmatic. Here, we show that one such assembly factor, the conserved protein FliL, forms an integral part of the flagellar motor in a position that colocalizes with the stator. Cryogenic electron tomography reconstructions of the intact motor in whole wild-type cells and cells lacking FliL revealed that the periplasmic domain of FliL (FliL-C) forms 18 circumferentially positioned rings integrated with the 18 MotAB units. FliL-C formed partial rings in the crystal, and the crystal structure-based full ring model was consistent with the shape of the rings observed in situ. Our data suggest that each FliL ring is coaxially sandwiched between the MotA ring and the dimeric periplasmic MotB moiety of the stator unit and that the central hole of the FliL ring has density that is consistent with the plug/linker region of MotB in its extended, active conformation. Significant structural similarities were found between FliL-C and stomatin/prohibitin/flotillin/HflK/C domains of scaffolding proteins, suggesting that FliL acts as a scaffold. The binding energy released upon association of FliL with the stator units could be used to power the release of the plug helices. The finding that isolated FliL-C forms stable partial rings provides an insight into the putative mechanism by which the FliL rings assemble around the stator units.

PubMed: 35046042
DOI: 10.1073/pnas.2118401119

実験手法

X-RAY DIFFRACTION (2.1 Å)