Bacteria are really just like office workers, according to biologists at the University of Leeds. To put it simply, bacteria have instructions that tell them what to do and they must shred the instructions after the task is complete. Otherwise, they can be overwhelmed. This has given researchers hope that by blocking their “paper shredders” we may be able to control antibiotic resistant E coli.
"Bacteria are constantly firing off instructions telling the molecular factories inside them what to do, and where and when to do it,” says Dr Kenneth McDowall. “It is absolutely critical in this situation, not only for the factories to act on those instructions, but to destroy them once they have been completed. Otherwise, everything becomes chaotic.”
"I am sure anyone who has ever worked in an office will relate to this,” McDowall continues. “If you come back from holiday and find lots of messages, you struggle to work out which ones should be given priority. It would be much easier if the obsolete ones were automatically destroyed."
To deal with the situation McDowall says bacteria have developed the equivalent of an automatic shredder. Those more used to the paperless offices may think of it as a service to delete obsolete work emails.
The enzyme Ribonuclease E (RNase E) plays the role of shredder, deleting messenger RNA that would otherwise keep the factories spitting out proteins that are no longer needed. However, the mechanism for this has not been understood until now. McDowall’s team has published a paper in Nucleic Acids Research showing that RNase E cuts the messages in ways that prevents them being re-read, allowing them to sort the urgent new arrivals from the obsolete missives.
"Contrary to current models, ‘direct entry’ cleavage is a major pathway for degrading and processing RNA," the authors write. Combined with the method RNase E uses to bind to multiple RNA regions simultarnously, "These simple requirements may maximize the rate of degradation and processing by permitting multiple sites to be surveyed directly."
Justin Clarke, one of McDowall’s students and lead author of the paper says, "We are now 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."
The Leeds team have other ideas on how the information could be used as well.
“One of the most exciting developments in biology is the creation of synthetic organisms that are completely controlled by man-made instructions,” says co-author Dr Louise Kime. “Our work provides us with clues as to how instructions can be made so that they persist long enough to be read, but not so long that they result in information overload."
