New research unites RNA world and thioester theories on life’s origin

Scientists at University College London have unveiled a key chemical process that could explain how life began four billion years ago. Their research demonstrates the spontaneous formation of peptides through the union of RNA molecules and sulfur-rich thioester compounds under primordial Earth conditions.

The study bridges two major origin theories that have divided scientists for decades: the RNA world hypothesis, which emphasizes RNA’s role in self-replication, and the thioester world, which highlights sulfur compounds as metabolic energy sources.

How did RNA and sulfur compounds interact to form peptides?

The team discovered that amino acids attached to a sulfur-bearing small molecule called pantetheine can spontaneously bind to RNA at the key sites necessary for peptide formation.

This reaction occurred in water at neutral pH, closely mimicking the conditions of ancient pond and lake environments.

Previously, attempts to link amino acids with RNA failed because amino acids tended to bond with one another or break down in watery environments.

Using thioesters, the researchers overcame these obstacles, revealing a plausible pathway for early protein synthesis.

Did you know?
Pantetheine, a sulfur-bearing molecule, likely formed under early Earth conditions and enabled amino acid attachment to RNA.

What challenges did researchers overcome in the study?

A primary challenge was preventing amino acids from reacting among themselves rather than binding to RNA. Additionally, the reactions had to be stable in water, which had caused breakdowns in earlier experiments.

The introduction of pantetheine and thioesters created activated compounds that solved these problems.

This breakthrough step demonstrated that RNA and sulfur chemistry could have coexisted and cooperated in early life, overturning the notion that these theories are mutually exclusive.

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Why is this discovery a major breakthrough in origin of life research?

The chemical pathway shown closely parallels modern biological protein synthesis, suggesting that early life’s fundamental molecular processes may have emerged simultaneously rather than sequentially.

It offers the first insight into how amino acids could have naturally linked onto RNA to form peptides, key to evolving genetic coding and metabolism.

What are the next steps in understanding protein synthesis origins?

Scientists now aim to investigate how RNA sequences might selectively bind specific amino acids, paving the way for the genetic code’s emergence. Further experiments will test these interactions under varied conditions simulating early Earth.

This research opens new horizons in synthetic biology and the search for life beyond Earth, providing a chemical foundation for understanding how life began.