Elucidation of the directional switching mechanism of the bacterial flagellar motor

2014 Fiscal Year Final Research Report

• Project/Area Number: 24570131
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural biochemistry
• Research Institution: Osaka University
• Principal Investigator: MIYATA Tomoko 大阪大学, 生命機能研究科, 特任助教(常勤) (30423156)
• Co-Investigator(Renkei-kenkyūsha): MATSUNAMI Hideyuki 沖縄科学技術大学院大学, 細胞膜通過輸送研究ユニット, 研究員 (80444511)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 単粒子解析 / 電子顕微鏡 / 分子モーター

Outline of Final Research Achievements

Many bacteria swim by reversibly rotating flagella. The switch complex consists of three switch proteins, FliG, FliM and FliN which control counter clockwise-clockwise (CCW/CW) switching of the motor rotation, form the C-ring on the cytoplasmic face of the MS ring. CheY is a response regulator in bacterial chemotaxis, and phosphorylated CheY (CheY-p) binds to FliM and changes the rotational direction from CCW to CW. We report the C ring structures locked in CCW (che deletion strain) and CW (FliG ΔPAA strain). Comparison of the two strucures showed differences in the position of the C ring and the subunit arrangement in its outer wall. FliM and FliN were well fitted into the middle and lower parts of the outer ring of the C-ring, but the location of FliG remains uncertain. We report the FliG labelling experiments and the structure analysis of the CheY-p bound C ring by electron cryomicroscopy.

Free Research Field

構造生物学