Elucidating flagellar motor ion transfer process
University of Tokyo researchers have constructed the atomic model structure of the protein complex that corresponds to the stator (stationary part of a motor that surrounds the rotating part of a motor) of the E. coli flagellar motor for the first time by molecular simulation based on previously published experimental data, and elucidated the mechanism by which ions, including hydrogen ions (protons), are transferred through the stator.
Proton permeation through flagellar motor stator complex MotA/B. Based on the model of the three-dimensional structure of MotA/B identified in this research, protons can permeate through the gate (green) of the motor by diffusion of hydronium ions (blue), which induces the formation of a water wire (red and white) that may mediate the proton transfer to the proton binding site (yellow). © 2015 Yasutaka Nishihara and Akio Kitao.
Bacteria such as E. coli and Salmonella swim by rotating flagellar motors and filaments, which highly efficiently utilize the energy originating from the difference in ion concentration between the cell interior and exterior.
Among the bacterial flagellar motors, some convert the energy by the permeation of protons through the motor stator, while others utilize sodium ions or multiple ions. However, the atomic structure of the bacterial flagellar motor remained unknown, and the mechanism of ion permeation had not been elucidated in detail.
Project Researcher Nishihara Yasutaka at the Graduate School of Arts and Sciences and Associate Professor Akio Kitao at the Institute of Molecular and Cellular Biosciences constructed a three-dimensional model structure of the protein complex that comprises the flagellar motor stator MotA/B, and found that protons permeate through the transmembrane stator as hydronium ions, inducing a motion similar to a ratchet wrench (ratchet movement) limited to one directional rotation.
Investigation of this type of highly efficient energy conversion mechanism is essential to understand biological mechanisms which can utilize energy efficiently.
Nishihara Yasutaka and Akio Kitao, "Gate-controlled proton diffusion and protonation-induced ratchet motion in the stator of the bacterial flagellar motor", Proceedings of the National Academy of Science of the United States of America Online Edition: 2015/6/9 (Japan time), doi: 10.1073/pnas.1502991112.
U Tokyo Research article
Euan McKay | ResearchSEA
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences