Scientists have revised the origin of life on Earth

Exploring RNA PeptidesAccording to the new concept of LMU chemists led by Thomas Carell, it was a new molecular species consisting of RNA and peptides that began the evolution of life into more complex forms. Discuss Scientists have revised the emergence of life on Earth

One of the main reasons for the emergence of life on earth is based on the so-called idea of ​​the RNA world, which was formulated by molecular biology pioneer Walter Gilbert in 1986. According to this hypothesis, nucleotides – the basic building blocks of nucleic acids A, C, G and U – arose from a primeval soup, and then short RNA molecules were formed from nucleotides. These so-called oligonucleotides were already able to encode small amounts of genetic information.

Because such single-stranded RNA molecules could also combine into double strands, this raised the theoretical possibility that the molecules could replicate, that is to reproduce. In the course of evolution, this replication could improve and at some stage lead to the emergence of more complex life.

It's unclear how RNA molecules could connect to the world of proteins, for which we know the genetic material provides the blueprints. In a new paper published in the journal Nature, Carell's team has discovered a way that such a connection could occur.

Carell's group discovered that these non-canonical nucleosides are the key ingredient that allows the RNA world to connect with the protein world. Some of these molecular fossils, when found in RNA, can “decorate” single amino acids or even small chains of them (peptides), according to Carell. This leads to the formation of small chimeric RNA-peptide structures when amino acids or peptides are in solution at the same time as RNA. In such structures, the amino acids and peptides associated with RNA then even react with each other, forming ever larger and more complex peptides. nuclei in RNA, forming a nucleus on which long peptide chains can grow. On some RNA strands, peptides even grew at several points.

“It is possible that the RNA world was never pure, and RNA and peptides coexisted in one molecule from the very beginning,” they said scientists. Thus, we must expand the concept of the world of RNA to the concept of the world of RNA peptides. Peptides and RNA mutually supported each other during evolution, a new idea suggests.