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 Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Targeting headaches and tumors with nano-submarines

20.07.2018 | Health and Medicine

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>