Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bacteria pack their own demise

03.08.2009
Numerous pathogens contain an 'internal time bomb', a deadly mechanism that can be used against them.

After years of work, VIB researchers at the Vrije Universiteit Brussel (VUB) were able to determine the structure and operating mechanism of the proteins involved.

This clears the road for finding ways to set the clock on this internal time bomb and, hopefully, in the process developing a new class of antibiotics. The research was accepted for publication by top journal Molecular Cell, with congratulations from the editorial board.

It's in the genes

For years, Nathalie De Jonge, Remy Loris and their colleagues of the VIB Department of Molecular and Cellular Interactions at VUB, have applied their relentless dedication to the study of the precise structure and function of the toxin-antitoxin complex, a system that had not been the focus of much interest in the past. Only in the last couple of years the rest of the scientific world come to realize its importance and as a result the number of papers in this field has exploded.

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 meters, while bacteria have to make do with around one millimetre 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.

Toxin and antitoxin

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.

Our best-known intestinal residents, Escherichia coli bacteria, more commonly known as E.coli, have such a T-A system in five different locations in their DNA, while Mycobacterium tuberculosis bacteria even have them in 60 locations.

A difficult feat

The T-A mechanism has been known for a while, but nobody clearly understood the workings of the proteins carrying out the instructions of the T-A gene. The VIB researchers clarified in detail both the appearance of the toxin and antitoxin, the mechanism of their interaction and the forms they take while in action – a difficult feat to pull off, requiring the simultaneous use of a whole range of different technologies. One of the difficulties for instance lay in the fact that part of the antitoxin lacks a fixed structure. This formlessness keeps it from being brought into view.

Future

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, i.e. substances that imitate the toxin protein, block the antitoxin protein, or disrupt the interaction between the toxin and antitoxin. In time, a new class of antibiotics might come out of it – though Nature mostly has a countermove up its sleeve against any move scientists do.

Pieter Van Dooren | EurekAlert!
Further information:
http://www.vib.be

Further reports about: DNA DNA strand Escherichia coli Molecular Target T-A VIB VUB bacteria genetic information

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>