Featured Research

from universities, journals, and other organizations

Researchers Describe Long-perplexing 'Magic Spot' On Bacteria

Date:
April 30, 2004
Source:
Ohio State University
Summary:
Scientists have unraveled the behavior of one key component of bacteria, a finding that may lead to better, more effective antibiotics.

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

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.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "Researchers Describe Long-perplexing 'Magic Spot' On Bacteria." ScienceDaily. ScienceDaily, 30 April 2004. <www.sciencedaily.com/releases/2004/04/040430054002.htm>.
Ohio State University. (2004, April 30). Researchers Describe Long-perplexing 'Magic Spot' On Bacteria. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2004/04/040430054002.htm
Ohio State University. "Researchers Describe Long-perplexing 'Magic Spot' On Bacteria." ScienceDaily. www.sciencedaily.com/releases/2004/04/040430054002.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Adorable Video of Baby Rhino and Lamb Friend Playing

Adorable Video of Baby Rhino and Lamb Friend Playing

Buzz60 (Oct. 20, 2014) Gertjie the Rhino and Lammie the Lamb are teaching the world about animal conservation and friendship. TC Newman (@PurpleTCNewman) has the adorable video! Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins