Scientists discovered a new protein which allows bacteria to become dormant under severe conditions. This process makes bacteria virtually indestructible and explains how bacteria survives in places that are uninhabitable, such as in space, under permafrost or the depths in oceans. The ability to sporulate (also known as “sporulation”) is what allows superbugs, which are resistant to hospital cleaning, to survive and come to life again in the stomachs of patients who have been compromised. Scientists hope that the discovery of a protein in bacteria involved in sporulation will help them better understand bacteria and their ability to thrive in spite of all odds. They may even be able to develop new antimicrobial treatments. Two separate articles published today in Genes and Development examine Bacillus, a group that includes cereus bacteria, responsible for food-poisoning and anthrax. Scientists from King’s College London’s Department of Chemistry worked with scientists at the University of California San Diego and the Max Planck Unit for the Science of Pathogens, Berlin. Mount Holyoke College, in the USA, was also part of the research team. Professor Rivka Isaacson is the co-author and said that: ” “We have known for a long time that bacteria are able to perform metabolic shut-down in unfavourable environments, transforming into long-lived, indestructible dormant spores which can survive for thousands of years.”
“This happens through asymmetrical cell division, where the bigger part — the ‘mother cell’ — engulfs the smaller part, the ‘forespore’, providing it with nutrients and a protective outer layer. It continues to build up protective layers around its genetic materials until it is ready to be released as a spore.”
While this process has been well studied, the mechanism behind shutting metabolism was a mystery, until scientists found a protein, MdfA, which had never before been characterised.
According to Professor Isaacson, “Every cell contains a recycling centre called a protease that is responsible for breaking old or damaged protein down. MdfA, a previously unknown protein that acts as an adaptor to recruit the proteins for recycling was discovered by us. After identifying MdfA, King’s chemists solved the crystal structure using x-rays, which revealed a new molecular form. They were able to better understand the way MdfA interacts with a portion of the recycling chute within cells called ClpC. Scientists also discovered that overexpressing MdfA in cells caused them to burst. ClpC, the recycling machine, and MdfA are present in many other types of bacteria. This suggests that similar proteins could be responsible for sporulation, even in bacteria which cause diseases. Professor Isaacson stated:
Scientists also hope that their findings could lead to the development of new antimicrobials.
Professor Isaacson added: “If you can target the cell degradation machinery to remove particular proteins, this can open new avenues for anti-microbial therapies, similar to an emerging form of cancer treatment, known as targeted protein degradation or PROTAC, which repurposes a cell’s recycling system for therapy.”
