Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers describe long-perplexing ’magic spot’ on bacteria

30.04.2004


Scientists have unraveled the behavior of one key component of bacteria, a finding that may lead to better, more effective antibiotics.


Irina Artsimovitch



The researchers studied a mechanism of action they call the "magic spot" – an important regulator of gene expression. They describe their results in the current issue of the journal Cell.

Researchers know that the magic spot – a molecule known as guanosine-tetraphosphate or ppGpp – is involved in how bacteria respond to amino acid starvation. More recently, researchers have discovered that ppGpp is an important part of pathogens that cause illnesses such as cholera and Legionnaires’ disease.


A cell makes ppGpp when amino acid levels are low.

"Microbiologists have wondered for a half-century how this small molecule with a relatively simple structure could have such a profound effect on regulating a cell’s survival," said Irina Artsimovitch, a study co-author and an assistant professor of microbiology at Ohio State University. She collaborated on this work with study lead author Dmitry Vassylyev, of the RIKEN Institute in Japan.

ppGpp controls what researchers call the "stringent response" – a condition of nutritional starvation. When amino acid pools in a cell are exhausted, ppGpp accumulates and shuts down the synthesis of new proteins. The cell goes dormant until amino acid levels return to normal.

By learning the structure of ppGpp and how it interacts with the enzyme RNA polymerase – the main enzyme that controls gene expression in a cell – the researchers were able to describe in detail the "magic" behind the magic spot, Artsimovitch said.

"This study sheds a good deal of light on the inner workings of the molecular machinery that carries out gene expression in bacteria," she said. "Knowing this can serve as a basis for a new type of antibiotics.

In related work reported in a recent issue of the Journal of Bacteriology, Artsimovitch led a team of researchers in learning how a protein that is specific to illness-causing bacteria might provide another potential path to developing antibiotics against bacteria that cause cholera, pneumonia and food poisoning.

This protein, called RfaH, regulates virulence – a bacterium’s ability to cause disease – in pathogens such as Escherichia coli and Salmonella enterica, bacteria that cause food poisoning in humans.

Artsimovitch and her colleagues identified previously overlooked RfaH genes in other bacterial pathogens, such as those that cause cholera and bubonic plague.

"Not only do RfaH proteins from different bacteria look similar, they act similar, too," she said.

Without RfaH, enterobacteria can’t cause disease, Artsimovitch said. It’s plausible that drug developers could design an antibiotic that knocks out RfaH, effectively shutting down a bacterium’s virulence.

"We’re trying to give the scientists who work on these pathogens detailed models of RfaH and ppGpp behavior," Artsimovitch said. "That may lead to better-targeted antibiotics that can really be effective against these diseases."

Support for these studies came from the American Heart Association and the National Institutes of Health.

Artsimovitch and Vassylyev conducted the work reported in Cell with researchers from the RIKEN Harima Institute in Hyogo, Japan; the RIKEN Genomic Sciences Center in Yokohama, Japan; the National Food Research Institute in Ibaraki, Japan; and the University of Tokyo. Artsimovitch conducted the work reported in the Journal of Bacteriology with Ohio State researchers Heather Carter and Vladimir Svetlov.


Contact: Irina Artsimovitch, (614) 292-6777;
Artsimovitch.1@osu.edu
Written by Holly Wagner, (614) 292-8310; Wagner.235@osu.edu

Holly Wagner | OSU
Further information:
http://researchnews.osu.edu/archive/shutbac.htm

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>