| Project/Area Number |
17076005
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Tohoku University (2006-2009)
Nagoya University (2005) |
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Principal Investigator |
ISHIJIMA Akihiko Tohoku University, 多元物質科学研究所, 教授 (80301216)
|
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGISHI Ikuro 法政大学, 工学部, 教授 (80234037)
HOMMA Michio 名古屋大学, 理学研究科, 教授 (50209342)
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| Project Period (FY) |
2005 – 2009
|
| Project Status |
Completed (Fiscal Year 2009)
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| Budget Amount *help |
¥82,500,000 (Direct Cost: ¥82,500,000)
Fiscal Year 2009: ¥15,200,000 (Direct Cost: ¥15,200,000)
Fiscal Year 2008: ¥15,400,000 (Direct Cost: ¥15,400,000)
Fiscal Year 2007: ¥15,500,000 (Direct Cost: ¥15,500,000)
Fiscal Year 2006: ¥17,400,000 (Direct Cost: ¥17,400,000)
Fiscal Year 2005: ¥19,000,000 (Direct Cost: ¥19,000,000)
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| Keywords | バクテリア / べん毛モーター / ナノ計測 / イメージング / 回転計測 / GFP / 走化性 / モータータンパク / レセプター / 細胞内局在 / モーター / 1分子計測 / イオン / キメラ菌体 / イオンモーター / ステップ計測 |
|---|
| Research Abstract |
The bacterial flagellar motor is a rotary molecular machine that rotates the helical filaments that propel many species of swimming bacteria. The rotor is a set of rings up to 45nm in diameter in the cytoplasmic membrane3 ; the stator contains about ten torque generating units anchored to the cell wall at the perimeter of the rotor4, 5. The free-energy source for the motor is an inward directed electrochemical gradient of ions across the cytoplasmic membrane, the protonmotive force or sodium-motive force for H1-driven and Na1-driven motors, respectively. Here we demonstrate a stepping motion of a Na1-driven chimaeric flagellar motor in Escherichia coli6 at low sodium-motive force and with controlled expression of a small number of torque-generating units. We observe 26 steps per revolution, which is consistent with the periodicity of the ring of FliG protein, the proposed site of torque generation on the rotor7, 8. Backwards steps despite the absence of the flagellar switching protein CheY indicate a small change in free energy per step, similar to that of a single ion transit.
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