Featured Research

from universities, journals, and other organizations

Dangerous bacterium hosts genetic remnant of life's distant past

Date:
August 15, 2010
Source:
Yale University
Summary:
Within a dangerous stomach bacterium, researchers have discovered an ancient but functioning genetic remnant from a time before DNA existed.

This micrograph depicts Gram-positive C. difficile bacteria.
Credit: CDC / Janice Carr

Within a dangerous stomach bacterium, Yale University researchers have discovered an ancient but functioning genetic remnant from a time before DNA existed, they report in the August 13 issue of the journal Science.

To the surprise of researchers, this RNA complex seems to play a critical role in the ability of the organism to infect human cells, a job carried out almost exclusively by proteins produced from DNA's instruction manual.

"What these cells are doing is using ancient RNA technology to control modern gene expression," said Ron Breaker, the Henry Ford II Professor of Molecular, Cellular and Developmental Biology at Yale, investigator for the Howard Hughes Medical Institute and senior author of the study.

In old textbooks, RNA was viewed simply as the chemical intermediary between DNA's instruction manual and the creation of proteins. However, Breaker's lab has identified the existence and function of riboswitches, or RNA structures that have the ability to detect molecules and control gene expression -- an ability once believed to be possessed solely by proteins. Breaker and many other scientists now believe the first forms of life depended upon such RNA machines, which would have had to find ways to interact and carry out many of the functions proteins do today.

The new paper describes the complex interactions of two small RNA molecules and two larger RNA molecules that together influence the function of a self-splicing ribozyme, a structure many biologists had believed had no role other than to reproduce itself. The new study, however, suggests that in the pathogenic stomach bacterium Clostridium difficile, this RNA structure acts as a sort of sensor to help regulate the expression of genes, probably to help the bacterium manipulate human cells.

"They were thought to be molecular parasites, but it is clear they are being harnessed by cells to do some good for the organism," Breaker said.

This is the sort of RNA structure would have been needed for life to exist before the evolution of double-stranded DNA, with its instruction book for proteins that carry out almost all of life's functions today. If proteins are necessary to carry out life's functions, scientists need to explain how life arises without DNA's recipe. The answer to the chicken or egg question is RNA machines such as the one identified in the new study, Breaker said.

"A lot of sophisticated RNA gadgetry has gone extinct but this study shows that RNA has more of the power needed to carry out complex biochemistry," Breaker said. "It makes the spontaneous emergence of life on earth much more palatable."


Story Source:

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


Journal Reference:

  1. Elaine R. Lee, Jenny L. Baker, Zasha Weinberg, Narasimhan Sudarsan, and Ronald R. Breaker. An Allosteric Self-Splicing Ribozyme Triggered by a Bacterial Second Messenger. Science, 13 August 2010: 845-848

Cite This Page:

Yale University. "Dangerous bacterium hosts genetic remnant of life's distant past." ScienceDaily. ScienceDaily, 15 August 2010. <www.sciencedaily.com/releases/2010/08/100812151630.htm>.
Yale University. (2010, August 15). Dangerous bacterium hosts genetic remnant of life's distant past. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2010/08/100812151630.htm
Yale University. "Dangerous bacterium hosts genetic remnant of life's distant past." ScienceDaily. www.sciencedaily.com/releases/2010/08/100812151630.htm (accessed October 2, 2014).

Share This



More Fossils & Ruins News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Battle of New Orleans Cannon Gets New Carriage

Battle of New Orleans Cannon Gets New Carriage

AP (Sep. 30, 2014) A Spanish cannon used in the Battle of New Orleans and weighing nearly 3 tons was lowered Tuesday by pulleys, chains and muscle onto a new gun carriage like one that might have held it once aboard a navy ship. (Sept. 30) Video provided by AP
Powered by NewsLook.com
2,000 Year Old Pre-Inca Cloak on Display in Lima

2,000 Year Old Pre-Inca Cloak on Display in Lima

AFP (Sep. 27, 2014) A 2,000 year-old Pre-Inca cloak that is believed to represent an agricultural calendar of the Paracas culture is on display in Lima. Duration: 00:39 Video provided by AFP
Powered by NewsLook.com
Original Mozart Sonata Manuscript Found in Budapest

Original Mozart Sonata Manuscript Found in Budapest

AFP (Sep. 26, 2014) Considered lost for over two centuries, the original manuscript of one of the most famous works of Mozart's Sonata in A major has been uncovered in a library in Budapest. Duration: 01:04 Video provided by AFP
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