Research by the Scripps Research Institute, USA, provides more evidence for the hypothesis that DNA plays an important role in the formation of life on Earth.
The process of forming life on Earth has always been a subject of fascination for scientists. However, going back billions of years is not easy, if not impossible.
However, thanks to the development of science and technology, there is more and more evidence to support a new hypothesis about how life began: the exact mix of RNA and DNA.
Both RNA and DNA play a role in determining the genetic makeup of life, where DNA is like the genetic blueprint and RNA is the set to read or decode that blueprint.
RNA and DNA together with lipids, proteins, and carbohydrates, form the four types of macromolecules that are the basis for all life on Earth.
For a long time, the scientific world relied on the “RNA World” theory when talking about the formation of the Earth.
According to this theory, about 4 billion years ago, when Earth was still a planet filled with toxic gases and volcanic eruptions, a self-replicating molecule appeared.
This is evolution, the beginning of life. Scientists in the 1960s believed that the first molecule had the nature of RNA.
However, from the evidence collected recently, it is likely that RNA and DNA appeared at the same time and were involved in the formation of life on the planet.
A new study explains how the simple compound diamidophosphate (DAP) , a compound that may have predated life on Earth, knitted the building blocks of deoxynucleoside together to form basic strands of DNA.
New research proves that RNA and DNA combine to create life. (Photo: 123 RF).
Chemist Ramanarayanan Krishnamurthy, of the Scripps research group in California, US, said: “This discovery is an important step towards the development of a chemical model of how the first life forms formed on Earth. “.
The findings from the study lend credence to the idea that DNA and RNA evolved together from the same type of chemical reaction, and that the first molecules may be a mixture of both of these nucleic acids, not just RNA as previously assumed.
The previous “RNA world” theory still did not answer the question of how RNA could self-replicate because it required enzymes to initiate the cleavage process.
With what is known from the new study, it appears that DNA is involved in this process by creating chimeric filaments, making separation easier than a single RNA strand would do on its own.
A series of tests conducted by the researchers simulated how the DAP compound forms the basic DNA strand, similar to the way RNA strands join together.
Chemist Ramanarayanan Krishnamurthy. (Photo: NRI Pulse).
“We were surprised to find that the reaction between the DAP compound and the deoxynucleoside was better when the deoxynucleosides were not identical but instead had a combination of DNA fragments such as A and T, or G and C, like like a real strand of DNA,” said chemical biologist Eddy Jiménez, from Scripps Research.
In the end, we may never know for sure whether DNA helped RNA form the first life forms. But this new study is an evolution in the discovery of the origin of life.
In addition, understanding the relationship between RNA and DNA helps create many different applications for modern biological and chemical research.
“Now that we have a better understanding of how a primitive chemistry makes RNA and DNA, we can begin to apply this formula to a mixture of ribonucleoside and deoxynucleoside building blocks, to see chimeric molecules. will form and whether they can self-replicate or evolve,” Krishnamurthy said.
Details of the study are available on the Angewanted Chemie page.