Bacteria have fascinating ways of surviving, and one critical process involves how they collect essential nutrients. This study dives into the workings of a unique bacterial mechanism called the Ton system, which functions like a molecular machine to pull nutrients into the cell. By using the energy difference created by protons—tiny charged particles—inside and outside the cell, this system helps bacteria gather important resources like vitamins and metals. These insights could pave the way for new antibacterial treatments.
Led by Dr. Nadia Izadi-Pruneyre in collaboration with scientists from the Institut Pasteur and other partner organizations conducted this groundbreaking research. Their study focused on a specific part of the Ton system called ExbD, examining how it moves and changes to help the system work. Published in Nature Communications, this research also highlights the key role of the bacterial cell wall, known as peptidoglycan, a mesh-like structure that provides support and protection to bacteria, in making this process possible.
The team found that ExbD works in pairs and constantly switches between two shapes: open and closed. These changes are necessary for another protein, TonB, to supply the power needed to move nutrients through the bacterial outer layer. Using advanced imaging techniques called nuclear magnetic resonance spectroscopy, which is a method to visualize the structure of molecules at the atomic level, the researchers showed that the “open” shape of ExbD activates TonB, which then reorganizes to start the nutrient-transport process.
Bacterial cell walls also play an important role in this mechanism. Dr. Izadi-Pruneyre shared, “We discovered that the way ExbD changes shape is directly linked to its ability to help bacteria take in nutrients. Our work also shows that the peptidoglycan layer of the bacterial cell wall helps anchor and support this process.” The study introduces a new model that explains how this cell wall layer interacts with ExbD to ensure the system runs smoothly.
The findings could have big implications for fighting bacterial infections. Because the Ton system is crucial for bacteria to survive, understanding its inner workings could lead to innovative ways to stop harmful bacteria. Targeting the system’s weak points—such as disrupting the energy transfer or blocking ExbD’s movements—might prevent bacteria from collecting the nutrients they need to grow and spread.
Dr. Izadi-Pruneyre emphasized, “Our research closes important gaps in understanding how bacterial systems like this work and identifies potential new ways to target bacterial defenses.” The study also suggests that other bacterial systems, which help them move or maintain their structure, may use similar processes.
With antibiotic resistance becoming a major global problem, this research marks an important step toward creating better treatments. Decoding the details of how bacteria survive reveals both their ingenuity and vulnerabilities, making the Ton system a promising focus for developing next-generation antibiotics.
Journal Reference
Maximilian Zinke, Maylis Lejeune, Ariel Mechaly, Benjamin Bardiaux, Ivo Gomperts Boneca, Philippe Delepelaire & Nadia Izadi-Pruneyre. “Ton motor conformational switch and peptidoglycan role in bacterial nutrient uptake.” Nature Communications. (2024). DOI: https://doi.org/10.1038/s41467-023-44606-z
