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Past Projects
RNA
ATP
Ultrashort Pulse Laser
Spatio-Temporal
Membrane Mechanisms
Quantum Spin Information
Organ Regeneration
Computational Brain
Nanoscale Quantum Conductor Array
Dynamic Nanomachine
Entropy Control
Calcium Oscillation
Photon Craft
Cell Mechanosensing
Bio-Recycle
Quantum Entanglement
Development of HIV/AIDS vaccine for HIV-1 Subtype-E
Single Molecule Processes
Nanotubulites
Chemotransfiguration
Cold Trapped Ion
Mind Articulation
NeuroGenes
Ceramics Superplasticity
Quantum Transition
Subfemtomole Biorecognition
Supermolecules
Microbial Evolution
Atom Arrangement-Design and Control for New Materials
2002.12-2007.12 Dynamic Nanomachine Project
Japan-U.S.A.
Research Directors
Prof. Keiichi Namba Prof. Keiichi Namba
Graduate School of Frontier Biosciences, Osaka University
May Macnab   May Macnab
Research Faculty, Yale University

Counterpart Organization: Yale University(U.S.A)

From unicellular organisms to human, biological motion, which is a fundamental function of living system, is driven by complex structures composed of biological macromolecules, such as proteins and nucleic acids. They are called ‘dynamic nanomachine’ and the bacterial flagellum is one of them. The flagellum rotates very fast and controls bacterial motility. The flagellum is an ultra-efficient motor far beyond artificial motors, and constructed through a flexible self-assembly mechanism.

In this research project, we aimed at understanding of the self-assembly mechanism of nano-structure and the ultra-efficient conversion mechanism of extremely small energy through the studies of molecular structure, dynamics and formation of the bacterial flagellum. To analyze the flagellum at nanoscale precision, we developed experimental techniques of X-ray structural analysis, electron cryo-microscopy and optical nano-photometry. We determined the structures of the helical screw, which is the main-body of the flagellum, the universal joint connecting the screw and the drive shaft of the motor, and the flagellar protein export apparatus. We revealed the mechanism of flagellar protein export, which is essential for the flagellar self-assembly, and roles of ATP hydrolyzing energy and proton motive force on the protein export.

This research project was carried out in complementary collaboration with Yale University in US. The Japanese group investigated the structure, function and dynamics of the flagellum, and the US group produced large amount of flagellar component proteins by genetic manipulation and provided various samples for the structural analysis. The highly efficient energy-conversion mechanism of living system reveled by this project must contribute to establish bases of biotechnology towards design and creation of artificial nano-machines in future.

Japan Science and Technology Agency
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