D_O_IC_R_E_D#Bactery
Electron microscopy images show important structures and mechanisms inside the molecular machines that some bacteria use to move
When we think of motors, most people think of cars or machines.
But biological motors have existed for millions of years in microorganisms.
Many bacteria have tail-like structures called flagella that rotate to help them move through liquids.
This movement is produced by a set of proteins called the flagellar motor.
The flagellar motor has two main parts: the rotor and the stators.
The rotor is a large, rotating structure attached to the cell membrane that moves the flagellum.
The stators are smaller structures around the rotor that have channels through which ions, such as protons or sodium ions, pass, depending on the type of bacteria.
When these charged ions pass through the channels, the stators change shape and push the rotor, causing it to rotate.
Despite many studies on stators, it is still not entirely clear how these ion channels work.
A Closer Look at the Flagellar Motor of Vibrio alginolyticus
In this context, a research team led by Assistant Professor Tatsuro Nishikino of the Nagoya Institute of Technology analyzed the flagellar motor of the bacterium Vibrio alginolyticus.
The team also included Norihiro Takekawa and Katsumi Imada of Osaka University, Jun-ichi Kishikawa of the Kyoto Institute of Technology, and Seiji Kojima of Nagoya University.
The results were published in the journal Proceedings of the National Academy of Sciences of the United States of America on December 30, 2024.
The scientists used an advanced technique called cryo-electron microscopy (cryoEM), which allows them to take very detailed pictures of biological molecules.
To do this, they quickly froze the bacteria and observed them with an electron microscope.
By analyzing normal and genetically modified V.
alginolyticus, the team was able to capture images of the stators at different times and identified important cavities through which sodium ions pass.
Based on this data, the researchers created a model that explains how sodium ions move through the stators.
In short, the subunits of the stators of Vibrio alginolyticus, organized in a ring, act as filters that allow only sodium ions to pass through, blocking other types of ions.
They also discovered how a substance called phenamyl, which blocks ion channels, prevents the movement of sodium ions through the stators.
Proposed Model for Sodium Ion Flow
The results of this study could be very useful in the medical field.
“Flagella-based movement is linked to infections and toxicity of some dangerous bacteria.
One of the reasons for doing this study was to find ways to deactivate these bacteria, limiting their ability to move.
Understanding how the flagellar motor works at the molecular level is essential for this,” explains Tatsuro.
Furthermore, knowledge about flagellar motors could inspire the creation of tiny machines.
“Flagellar motors are like molecular nanomachines, about 45 nanometers in diameter and with an energy efficiency of almost 100%.
Our results are a major advance in understanding how they generate force, which could be very important for developing molecular motors at the nanometer scale,” concludes Tatsuro.
We hope that new studies will help to clarify all the details of these incredible natural machines!
Published in 02/21/2025 19h20
Text adapted by AI (ChatGPT / Gemini) and translated via Google API in the English version. Images from public image libraries or credits in the caption. Information about DOI, author and institution can be found in the body of the article.
Reference article:
Original study:
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