| Budget Amount *help |
¥15,990,000 (Direct Cost: ¥12,300,000、Indirect Cost: ¥3,690,000)
Fiscal Year 2018: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2017: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2016: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
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| Outline of Final Research Achievements |
Motile archaea swim using a rotary filament, the archaellum, a surface appendage that resembles bacterial flagella structurally. Little is known about the mechanism by which archaella produce motility. In a series of studies supported by this grant, we characterized archaellar function in the model organism Halobacterium salinarum. Three-dimensional tracking of quantum dots enabled visualization of the left-handed corkscrewing of archaea in detail. An advanced analysis method was developed and revealed a right-handed helical structure of archaella with a rotation speed of 23 Hz. We also determined motor torque by imposition of various loads on archaella; markers of different sizes were attached to single archaella, and their trajectories were quantified. We show that rotation slows as the viscous drag of markers increases, but torque remains constant at 160 pN nm independent of rotation speed. A new and general model for the mechanism of ATP-driven rotary motors are finally suggested.
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