Researchers show RNA ribozymes able to cooperate to reassemble themselves

Oct 18, 2012 by Bob Yirka report

(Phys.org)—A team of chemistry and applied sciences researchers from several universities in the United States has shown that RNA fragments torn apart in the lab work together to reassemble themselves. This finding, the team claims in their paper published in the journal Nature suggests that early life may have started with cooperative efforts between RNA molecules eventually leading to cooperative replication.

The team based its work on mathematical theories proposed by Manfred Eigen, a who suggested that because early RNA wouldn't be able to successfully evolve from short stranded molecules, they must have had help. That help, he said, may have come in the form of cooperative efforts between molecules.

In earlier work team lead Niles Lehman had found that if long RNA molecules known as ribozymes were cut into fragments and then placed together in a Petri dish, they would over time reassemble themselves into their original configuration. In this new research, Lehman et al altered three samples so that they were identical save for one letter that allowed for distinguishing among them. Each was cut into two pieces and placed in a Petri dish. The team found that if the ribozymes were placed together in a , they reassembled themselves faster than if they were put in the dish alone. This occurred, they report, because one of the ribozymes helped another reassemble, who then helped a third reassemble who in turn helped the first reassemble, which formed a closed loop network.

To see if the same result might be possible in a more chaotic environment, the researchers placed 48 cut ribozymenes in a with millions of other RNA molecules and found that the original 48 found a way to locate their other parts and each other and helped one another reassemble; again much faster than any of them would have alone.

The team suggests that a similar type of cooperation among short RNA molecules in Earth's may have allowed them to replicate in a way that avoided the problem of building up mistakes when making copies that mathematical models have suggested would have led to evolutionary death. That would have allowed them to evolve into longer more complex and eventually into all the other molecules that exist today.

Explore further: Following a protein's travel inside cells is key to improving patient monitoring, drug development

More information: Spontaneous network formation among cooperative RNA replicators, Nature (2012) doi:10.1038/nature11549

Abstract
The origins of life on Earth required the establishment of self-replicating chemical systems capable of maintaining and evolving biological information. In an RNA world, single self-replicating RNAs would have faced the extreme challenge of possessing a mutation rate low enough both to sustain their own information and to compete successfully against molecular parasites with limited evolvability. Thus theoretical analyses suggest that networks of interacting molecules were more likely to develop and sustain life-like behaviour. Here we show that mixtures of RNA fragments that self-assemble into self-replicating ribozymes spontaneously form cooperative catalytic cycles and networks. We find that a specific three-membered network has highly cooperative growth dynamics. When such cooperative networks are competed directly against selfish autocatalytic cycles, the former grow faster, indicating an intrinsic ability of RNA populations to evolve greater complexity through cooperation. We can observe the evolvability of networks through in vitro selection. Our experiments highlight the advantages of cooperative behaviour even at the molecular stages of nascent life.

Related Stories

Life's origins were easier than was thought

Sep 15, 2005

An international team of scientists, leaded by Universitat Autònoma de Barcelona researchers, has discovered that RNA early molecules were much more resistant than was thought until now. According to the conclusions of the ...

Rehydrate -- your RNA needs it

Aug 22, 2006

Water, that molecule-of-all-trades, is famous for its roles in shaping the Earth, sustaining living creatures and serving as a universal solvent. Now, researchers at the University of Michigan and the Academy of Sciences ...

RNA reactor could have served as a precursor of life

Jul 11, 2011

(PhysOrg.com) -- Nobody knows quite how life originated on Earth, but most scientists agree that living cells did not abruptly appear from nonliving cells in a single step. Instead, there were probably a series ...

Researchers develop glowing probes to detect germs via RNA

Apr 04, 2012

(PhysOrg.com) -- A team of researchers from the Boston area have developed a “glowing probe” molecule that is able to detect the presence of many common types of bacteria, viruses and even fungi. The results of ...

Recommended for you

The anti-inflammatory factory

Apr 22, 2014

Russian scientists, in collaboration with their colleagues from Pittsburgh University, have discovered how lipid mediators are produced. The relevant paper was published in Nature Chemistry. Lipid mediators are molecules that p ...

Breakthrough points to new drugs from nature

Apr 16, 2014

Researchers at Griffith University's Eskitis Institute have developed a new technique for discovering natural compounds which could form the basis of novel therapeutic drugs.

User comments : 0

More news stories

Cyber buddy is better than 'no buddy'

A Michigan State University researcher is looking to give exercise enthusiasts the extra nudge they need during a workout, and her latest research shows that a cyber buddy can help.