Jamming bacterial ‘shredder’ could fight infection

By jamming their ‘paper shredder’, scientists might be able to drown deadly bacteria in their own paperwork. Researchers from the University of Leeds have identified how this paper shredder works to allow E. coli to keep on top of its day job. “If we block the ‘shredder’ using genetics in the lab, the bacteria drown in a flood of messages,” said Dr Kenneth McDowall, Associate Professor in Molecular Biology. “The challenge now if to block it with drugs so that bacterial infections in humans can be killed. Our latest results give up a good idea how this can be done.” The shredder in the harmless version of E. coli is an enzyme called RNas E, which was known to have a role in destroying messenger RNA copied from DNA, although its mechanism was not understood. The enzyme can cut at many sites internal to messages to prevent them being re-read. This shredding of the message helps explain how bacteria are able to prioritise the thousands of instructions required to replicate. “This ‘shredder’ helps the bacteria to respond quickly to its environment by making them focus on current rather than old messages,” said Justin Clarke. “We are not working on how to target RNase E with a new type of antibiotic drug. The exciting thing is that RNase E is found in many pathogenic bacteria as well as the harmless strain of E. coli we study in the lab.” But this discovery, published in Nucleic Acid Research, has implications beyond antibiotic design say the researchers. It also provides crucial information for synthetic biology. “One of the most exciting developments in biology is the creation of synthetic organisms that are completely controlled by man-made instructions,” said senior researcher Dr Louise Kime. “Our work  provides us with clues as to how instructions can be made so that they persist long enough to read, but not so long that they result in information overload.” Direct entry by RNase E is a major pathway for the degradation and processing of RNA in Echerichia coli