London, Aug 1 (Inditop.com) Numerous pathogens contain an ‘internal time bomb’, a deadly mechanism that can be used against them, a new study has found.
After years of work, Flanders Institute for Biotechnology (VIB) researchers at the Vrije Universiteit Brussels (VUB) worked out the structure and operating mechanism of the proteins involved.
This opens the way for manipulating this internal time bomb and hopefully developing a new class of antibiotics.
For years, Nathalie de Jonge, Remy Loris and their colleagues at the VUB assiduously studied the precise structure and function of the toxin-antitoxin (T-A) complex, a fringe area in research.
All living creatures, people as well as bacteria, store their genetic information in the same way, i.e. in the DNA.
Every human cell contains 46 neatly folded DNA strands that together measure two metres, while bacteria have to make do with around one mm of DNA.
A piece of DNA containing the recipe for one characteristic, such as “how to make citric acid” or “how to make hair curl”, is called a gene. Humans have several tens of thousands of genes.
If your genetic information becomes damaged, you have a good chance of becoming ill or even dying. This is also true for bacteria, which over time developed a handy way of providing extra protection to important genes — the toxin-antitoxin (T-A) system.
These T-A genes are tucked in near the genes to be protected. T-A genes contain instructions for both a toxin and its antitoxin. As long as the cell is producing both, all is well.
However, if for some reason the piece of DNA where the T-A gene is located gets damaged or lost, the production of toxin and antitoxin comes to a halt and a time bomb starts ticking.
Because the toxin is more stable than the antitoxin, it is broken down more slowly by the cell’s clean-up mechanisms. Once the antitoxin is all gone, there is still enough toxin left to kill the bacterium.
The upshot for the species is that bacteria that loses their T-A gene — and probably have sustained damage to the important genes just next to it — can no longer reproduce, said a VUB release.
Now that we finally know how the time bomb functions (or more exactly, one of the time bombs, as there are several closely related T-A systems), biomedical scientists can start looking for substances to start the time bomb of pathogens ticking.
A new class of antibiotics might come out of it.
The research is slated for publication in the journal Molecular Cell.
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