We get close to recreating the first step in the evolution of life

The goal of understanding how inert molecules gave rise to life is one step closer, according to researchers who have created a system of RNA molecules that can party replicate themselves. They say that one day it should be possible to achieve complete self -replication for the first time.

RNA is a key colleges when it comes to the origin of life, as it can throw store information such as and catalyze reactions such as proteins. Although not as effective as any of these, the fact that it can do is both means that Mayry scientists believe that life began with RNA molecules that were able to replicate themselves. “This was the molecule that ranks biology,” says James Attwater at University College London.

But creating self-replicating RNA molecules has been difficult. RNA can form double helicles such as DNA and can be copied in the same way by dividing a double helix into two and adding RNA letters to each tripod to create two identical helixs. The problem is that RNA -Dobble Helixs cling so strongly that it is difficult to keep the threads separate long enough to allow replication.

Now Attwates and his colleagues have found that sets with three RNA letters – triplets – bind strong enough for each string to take this rezipping. Three is the sweet place, says Attwater, as long sets are likely to introduce mistakes. So in the team’s system, an RNA enzyme is mixed in double-helix form with triplets.

The solution is made acidic and heated to 80 ° C (176 ° F) to separate the helix, enabling the triplets to mate and form “Rungs” of double helix. The solution is then made alkaline and cooled to -7 ° C (19 ° F). When the water freezes, the remaining liquid becomes heavily concentrated and the RNA enzyme becomes active and joins the triplets and forms a new tripod.

So far, researchers have only been able to replicate up to 30 letters of the 180-better long RNA enzyme, but they think that by improving the enzyme they can achieve complete replication.

Attwater says this “very simple molecular system” has some exciting properties. One is the possible connection between triplet RNA letters and the triplet code used to specific the sequence of proteins in cells today. “There can be a relationship between how biology used to copy its RNA and how biology uses RNA today,” he says.

In addition, the team found that the triplets would most likely be involved in natural replication in the past are those who bind the strongest. The first genetic code is that has consisted of this set of triplets – another exciting link.

The researchers believe that the kind of conditions needed to drive this process could occur naturally. Since it requires fresh water, it is most likely that it has been haped on land, perhaps in a geothermal system.

“The ingredients can be found on Earth today – Iceland Hot Springs may have mixed PHS, included some as sour as the ones we use,” says Attwater.

“RNA nucleotide triplets serve very specific features of translation in all cells,” says Zachary Adam at the University of Wisconsin-Madison, which means they are used to convey information. “This paper is interesting because it can point to a purely chemical role-a non-informing function-for RNA nucleotid triplesses that they could have earned before the emergence of a living cell.”