Will the secret of Earth’s first life be revealed? – Sciencetimes



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The origin of life that first appeared on Earth is one of the mysteries that scientists around the world have yet to discover. However, research has been published supporting a surprisingly new perspective on how the first life on Earth originated.

He showed that a simple compound called DAP, which existed on Earth even before the first living organisms, can chemically link components of DNA (deoxynucleosides) into strands of primitive DNA.

Research has been published supporting a surprisingly new perspective on how the first life on Earth arose. ⒸGetty Image Bank

The discovery by Scripps Laboratories in the United States is striking because DNA and RNA came together as products of similar chemical reactions, raising the possibility that the first self-replicating molecules were a mixture of the two. It is also significant because it provided a broader direction of how the self-replicating mixture of DNA and RNA evolved and spread on early Earth, and could become the “seed of mature life” today.

“This discovery is very important in the development of detailed chemical models of how the first life on Earth originated,” said Professor Ramanarayanan Krishnamurthy of the Scripps Institute who led the study.

Unlike the existing RNA world hypothesis

This discovery is also a hot topic, as it departs from the ‘RNA world hypothesis’, which has been almost orthodox in recent decades in the field of chemistry regarding the origin of life. The RNA world hypothesis is the theory that the first living organisms were born when RNA was produced in the early days of the earth and made RNA capable of self-replication. In other words, the RNA world hypothesis assumes that the earliest replicators were based on RNA and that DNA later emerged as a product of RNA life.

However, Professor Krishnamurti has partially questioned the RNA world hypothesis because RNA molecules can be too static to act as self-replicators. An RNA chain can attract other individual RNA blocks to form a kind of mirror image chain, but it is not good at separating new chains. However, modern organisms produce enzymes that can forcibly separate the twin strands of RNA or DNA. It was not clear how such an enzyme was able to self-replicate on an early Earth where it did not yet exist.

However, in a recent study, Professor Krishnamurti’s team found that some molecular strands of DNA and RNA can form complementary strands in a less sticky way so that they can be separated relatively easily. In a paper published in 2017, they also reported that DAP, an organic compound, could play an important role in binding ribonucleosides to strands of RNA. However, a new study published this time has shown that DAP can play the same role for DNA.

Understand early RNA and DNA production

The three essential components of early life are known to be the nucleotide chains that store genetic information, the amino acid fragments for basic cellular programs, and the lipids that form the walls of intracellular structures. The only compound capable of forming all three components remains a mystery, and it was Professor Krishnamurti, a scientist who published the results of a study called DAP.

In a 2017 study, Professor Krishnamurti’s team tested whether DAP phosphorylates essential components of living organisms under conditions that replicated the initial global environment. I have disclosed the facts. For the first time, the findings that DAP can bind not only RNA components but also DNA components were published in the latest issue of Angewandte Chemie, an international journal in the field of chemistry.

Professor Ramanarayanan Krishnamurthy of the Scripps Institute who led the study. ⒸThe Krishnamurthy Laboratory

“As we understand how primitive chemistry produced the first RNA and DNA, we can see how they can self-replicate and evolve,” Professor Krishnamurti said of the findings. He also argued that the findings could be used widely in practical science. For example, like PCR, which is the basis of the Corona 19 test, the technology of artificial DNA and RNA synthesis belongs to a vast global business, but it has limitations because it is based on relatively weak enzymes. However, a chemical method that can produce DNA and RNA without powerful enzymes, such as the results of this study, can be attractive in many situations.

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