Featured Research

from universities, journals, and other organizations

Textbook Explanation Of mRNA Translation May Need Rethinking

Date:
June 27, 2005
Source:
BioMed Central
Summary:
Our understanding of how messenger RNAs are translated into proteins is challenged by a new research published today in the Open Access journal, Journal of Biology. The study suggests that EF-G, the GTPase that facilitates tRNA translocation in bacteria, enters the ribosome bound to a different guanine nucleotide than previously thought -- GDP, not GTP. The ribosome itself then seems to act as the guanine-nucleotide exchange factor, not some as-yet-unidentified factor as previously assumed. This finding questions the prevailing model for RNA translocation.

Our understanding of how messenger RNAs are translated into proteins is challenged by new research published today in the Open Access journal Journal of Biology. The study suggests that EF-G, the GTPase that facilitates tRNA translocation in bacteria, enters the ribosome bound to a different guanine nucleotide than previously thought – GDP, not GTP. The ribosome itself then seems to act as the guanine-nucleotide exchange factor, not some as-yet-unidentified factor as previously assumed. This finding questions the prevailing model for RNA translocation.

Related Articles


According to the textbook model EF-G provides the energy needed for the translocation phase of translation by bringing GTP into the ribosome where GTP is subsequently hydrolysed into GDP.

Andrei Zavialov, Vasili Hauryliuk and Måns Ehrenberg from Uppsala University in Sweden first performed an important purification step ensuring that their GTP was not contaminated by GDP (and vice versa), as had been the case with previous studies using these purified components. They next measured the affinity of EF-G for GTP and GDP. Their results strongly suggest that EF-G is bound to GDP in the cytoplasm and that it binds to the pre-translocation complex - composed of the ribosome, tRNA and mRNA strand – as a EF-G-GDP complex. The ribosome itself then seems to act as a GTP exchange factor that swaps GDP for GTP, which results in a modification in the structure of the ribosome. This triggers partial translocation of the mRNA, which is completed after GTP hydrolysis. "Our results suggest that the ribosome plays a previously unidentified dual role of both guanine-nucleotide exchange factor and GTPase-activating protein" explain the authors. EF-G then detaches from the ribosome in its GDP-bound form, ready to be used again by another ribosome.

These findings differ radically from all previous models and as such may represent a considerable step forward in our understanding of translocation, a fundamental mechanism in protein synthesis and gene expression. RNA translation is a highly conserved mechanism and these results using a bacterial system are likely to be applicable to higher organisms as well. This should spur more research in the field to confirm or disprove the findings and give us a clearer picture of RNA translation. In particular, the present clarification of the translocation process at the biochemical level may allow a deeper understanding of how relative movements of the ribosomal subunits can accomplish thousands of translocation events without frame-shifting or loss of tRNA-bound nascent protein chains during peptide elongation.

###

This press release is based on the following article:

Guanine-nucleotide exchange on ribosome-bound elongation factor G initiates the translocation of tRNAs
Andrey V Zavialov, Vasili V Hauryliuk and Måns Ehrenberg

Journal of Biology 2005, 4:9 (27 June 2005)


Story Source:

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


Cite This Page:

BioMed Central. "Textbook Explanation Of mRNA Translation May Need Rethinking." ScienceDaily. ScienceDaily, 27 June 2005. <www.sciencedaily.com/releases/2005/06/050627061514.htm>.
BioMed Central. (2005, June 27). Textbook Explanation Of mRNA Translation May Need Rethinking. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2005/06/050627061514.htm
BioMed Central. "Textbook Explanation Of mRNA Translation May Need Rethinking." ScienceDaily. www.sciencedaily.com/releases/2005/06/050627061514.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) — Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Cambodian Capital's Only Working Elephant to Retire in Jungle

Cambodian Capital's Only Working Elephant to Retire in Jungle

AFP (Nov. 25, 2014) — Phnom Penh's only working elephant was blessed by a crowd of chanting Buddhist monks Tuesday as she prepared for a life of comfortable jungle retirement after three decades of giving rides to tourists. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Stray Dog Follows Adventure Racing Team for 6-Day Endurance Race

Buzz60 (Nov. 24, 2014) — A Swedish Adventure racing team travels to try and win a world title, but comes home with something way better: a stray dog that joined the team for much of the grueling 430-mile race. Jen Markham has the story. 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