2RRL

Solution structure of the C-terminal domain of the FliK

2RRL の概要

• エントリーDOI: 10.2210/pdb2rrl/pdb
• NMR情報: BMRB: 11423
• 分子名称: Flagellar hook-length control protein (1 entity in total)
• 機能のキーワード: flik, flhb, bacterial flagella motor, hook-length control, protein transport
• 由来する生物種: Salmonella typhimurium
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17773.78

構造登録者

Mizuno, S.,Tate, S.,Kobayashi, N.,Amida, H. (登録日: 2011-01-02, 公開日: 2011-05-18, 最終更新日: 2024-05-29)

主引用文献

Mizuno, S.,Amida, H.,Kobayashi, N.,Aizawa, S.,Tate, S.
The NMR structure of FliK, the trigger for the switch of substrate specificity in the flagellar type III secretion apparatus
J.Mol.Biol., 409:558-573, 2011

PubMed Abstract: The flagellar cytoplasmic protein FliK controls hook elongation by two successive events: by determining hook length and by stopping the supply of hook protein. These two distinct roles are assigned to different parts of FliK: the N-terminal half (FliK(N)) determines length and the C-terminal half (FliK(C)) switches secretion from the hook protein to the filament protein. The interaction of FliK(C) with FlhB, the switchable secretion gate, triggers the switch. By NMR spectroscopy, we demonstrated that FliK is largely unstructured and determined the structure of a compact domain in FliK(C). The compact domain, denoted the FliK(C) core domain, consists of two α-helices, a β-sheet with two parallel and two antiparallel strands, and several exposed loops. Based on the functional data obtained by a series of deletion mutants of the FliK(C) core domain, we constructed a model of the complex between the FliK(C) core domain and FlhB(C). The model suggested that one of the FliK(C) loops has a high probability of interacting with the C-terminal domain of FlhB (FlhB(C)) as the FliK molecule enters the secretion gate. We suggest that the autocleaved NPTH sequence in FlhB contacts loop 2 of FliK(C) to trigger the switching event. This contact is sterically prevented when NPTH is not cleaved. Thus, the structure of FliK provides insight into the mechanism by which this bifunctional protein triggers a switch in the export of substrates.

PubMed: 21510958
DOI: 10.1016/j.jmb.2011.04.008

実験手法

SOLUTION NMR