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 'Y' a protein unicorn might matter in glaucoma
23.10.2017 | Georgia Institute of Technology

nachricht Microfluidics probe 'cholesterol' of the oil industry
23.10.2017 | Rice 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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>