Swiss researchers reveal mitochondrial supercomplexes' structure and efficiency

Researchers at the University of Basel in Switzerland have made a significant discovery about mitochondria, the energy-producing parts of our cells. They used a technique called cryo-electron tomography to capture detailed images of mitochondrial structures. Their findings, published in the journal Science, reveal that proteins involved in energy production group together to form large structures known as "supercomplexes." These supercomplexes are essential for generating energy in cells. Mitochondria are found in nearly all living organisms, including plants, animals, and humans. They convert oxygen from breathing and nutrients from food into ATP, the energy currency of cells. For many years, the exact arrangement of energy-producing proteins inside mitochondria remained unclear. Led by Dr. Florent Waltz and Prof. Ben Engel, the research team created high-resolution images showing how these proteins are organized within the mitochondria. They discovered that the proteins cluster in specific membrane regions, forming supercomplexes that help pump protons across the mitochondrial membrane. This movement is crucial for ATP production. The researchers studied mitochondria in the algae species Chlamydomonas reinhardtii. They were surprised to find that these proteins were so well organized into supercomplexes, which may improve energy efficiency and reduce energy loss. In addition to supercomplexes, the team examined the inner membranes of mitochondria. They found that the membranes have many folds, which increases surface area to accommodate more respiratory complexes, similar to the structure of lung tissue. Looking forward, the researchers hope to understand why these respiratory complexes connect and how this connectivity boosts cellular respiration and energy production. Their work could lead to new insights in biotechnology and health, helping to explain how disruptions in these complexes may contribute to diseases in humans.