EMDB/PDB/SASBDBから引用されている文献のデータベース

キーワード
構造解析手法	All X線回折 NMR 電子顕微鏡小角散乱中性子線回折線維回折粉末回折赤外分光 EPR FRET 理論モデルハイブリッド
著者・登録者
ジャーナル
IF	>30 >20 >10 >5 all

タイトル	Two Distinct Conformations in 34 FliF Subunits Generate Three Different Symmetries within the Flagellar MS-Ring.
ジャーナル・号・ページ	mBio, Vol. 12, Issue 2, Year 2021
掲載日	2021年3月2日
著者	Norihiro Takekawa / Akihiro Kawamoto / Mayuko Sakuma / Takayuki Kato / Seiji Kojima / Miki Kinoshita / Tohru Minamino / Keiichi Namba / Michio Homma / Katsumi Imada /
PubMed 要旨	The bacterial flagellum is a protein nanomachine essential for bacterial motility. The flagellar basal body contains several ring structures. The MS-ring is embedded in the cytoplasmic membrane and ...The bacterial flagellum is a protein nanomachine essential for bacterial motility. The flagellar basal body contains several ring structures. The MS-ring is embedded in the cytoplasmic membrane and is formed at the earliest stage of flagellar formation to serve as the base for flagellar assembly as well as a housing for the flagellar protein export gate complex. The MS-ring is formed by FliF, which has two transmembrane helices and a large periplasmic region. A recent electron cryomicroscopy (cryoEM) study of the MS-ring formed by overexpressed FliF revealed a symmetry mismatch between the S-ring and inner part of the M-ring. However, the actual symmetry relation in the native MS-ring and positions of missing domains remain obscure. Here, we show the structure of the M-ring by combining cryoEM and X-ray crystallography. The crystal structure of the N-terminal half of the periplasmic region of FliF showed that it consists of two domains (D1 and D2) resembling PrgK D1/PrgH D2 and PrgK D2/PrgH D3 of the injectisome. CryoEM analysis revealed that the inner part of the M-ring shows a gear wheel-like density with the inner ring of C23 symmetry surrounded by cogs with C11 symmetry, to which 34 copies of FliF fitted well. We propose that FliF adopts two distinct orientations in the M-ring relative to the rest of FliF, with 23 chains forming the wheel and 11 chains forming the cogs, and the 34 chains come together to form the S-ring with C34 symmetry for multiple functions of the MS-ring. The bacterial flagellum is a motility organelle formed by tens of thousands of protein molecules. At the earliest stage of flagellar assembly, a transmembrane protein, FliF, forms the MS-ring in the cytoplasmic membrane as the base for flagellar assembly. Here, we solved the crystal structure of a FliF fragment. Electron cryomicroscopy (cryoEM) structural analysis of the MS-ring showed that the M-ring and S-ring have different rotational symmetries. By docking the crystal structure of the FliF fragment into the cryoEM density map of the entire MS-ring, we built a model of the whole periplasmic region of FliF and proposed that FliF adopts two distinct conformations to generate three distinct C11, C23, and C34 symmetries within the MS-ring for its multiple functions.
リンク	mBio / PubMed:33653894 / PubMed Central
手法	EM (単粒子) / X線回折
解像度	2.29 - 8.6 Å
構造データ	EMDB-30378: Salmonella FliF-FliG ring complex 手法: EM (単粒子) / 解像度: 8.6 Å EMDB-30379: 11-fold symmetry of Salmonella FliF-FliG ring complex 手法: EM (単粒子) / 解像度: 6.1 Å PDB-7cik: Structure of the 58-213 fragment of FliF 手法: X-RAY DIFFRACTION / 解像度: 2.29 Å
化合物	ChemComp-MRD: (4R)-2-METHYLPENTANE-2,4-DIOL / (4R)-2-メチル-2,4-ペンタンジオ-ル / 沈殿剤YM ChemComp-HOH*: WATER
由来	Salmonella enterica subsp. enterica serovar Typhimurium (サルモネラ菌) aquifex aeolicus (strain vf5) (バクテリア)
キーワード	MOTOR PROTEIN / Flagellar motor protein