Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mispairs in genetic material make protein synthesis more efficient

07.03.2006


So-called wobble pairs make RNA more reactive, enhancing protein production



The wealth of information contained in a strand of genetic material boils down to sequences of matched pairs of nucleotides that cellular machinery decodes to construct proteins.

Writing today in The Proceedings of the National Academy of Sciences, a University of Wisconsin-Madison bacteriologist reveals that mispaired nucleotides in transfer RNA actually make the molecule more adroit, enhancing its ability to build proteins. The paper also illustrates the dynamic nature of genetic material, which is not flat, like an illustration in a textbook, but twists and bends as it interacts with cellular machinery.


The mispairs, also called "wobble pairs," do not bind together as tightly as matched pairs bind, making transfer RNA "a compressed spring ready to be sprung," according to William McClain, a professor of bacteriology in the UW-Madison’s College of Agricultural and Life Sciences and the author of the PNAS paper. He notes that specific transfer RNA mispairs, which likely originally arose through natural mutation, are highly conserved across all kingdoms of life, providing evidence that they play an important role in making the molecule more reactive.

Genetic information is encoded in DNA, which is made up of matched base pairs of adenine and thymine, and guanine and cytosine - commonly denoted with the letters A, T, G and C. Cellular machinery transcribes the information from DNA into RNA - where the base uracil replaces thymine -- and then translates the coded data into proteins, which form the building blocks of life.

Scientists have long known that transfer RNA - which adds amino acids to a growing chain during protein synthesis - holds a surprising secret when it comes to its base pairs: occasionally, instead of the expected A-U or G-C pairs, there exists instead a mispair of A-C or G-U. However, the role and importance of mispairs has never been well understood, says McClain.

McClain, who has spent his career investigating how transfer RNA selects specific amino acids during protein synthesis, was curious about how mispairs affect the function of RNA. In the study reported in PNAS, he altered the position of a G-U mispair in a bacterial plasmid - by literally moving the mispair up and down the molecule’s cloverleaf structure -- and demonstrated that the mutation increases the ability of the RNA to accept amino acids and improves its efficiency at moving through the ribosome, the cellular organelle where translation occurs. In fact, removing the mispair or repairing it to make it a correct matched pair inactivated the molecule completely.

"The wobble pairs fit together at an angle and the bonds are much less stable than matched pairs," McClain explains. "This makes the molecule more likely to come undone, and therefore more reactive."

This is crucial because DNA and RNA molecules are not the static, flat images that are depicted in textbooks, McClain notes. "They flex, move and come apart all the time," he says. "And mispairs promote this movement. My interpretation is that nature conserves these mispairs because they enhance protein synthesis."

McClain adds that he views his work as both an intellectual challenge as well as "tremendous fun."

"What biologists want to do is understand a cell in terms of all of its workings," he says, "just as when you take your car to a mechanic they have to know how it’s made. I want to know how a molecule is made, and how its parts come together."

William McClain | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>