New Study Reveals How RNA Could Have Fueled Protein Formation in Early Life

Proteins are essential for life, but their synthesis relies on RNA and complex molecular machinery such as enzymes and ribosomes. How the very first proteins emerged before these systems evolved has long remained a mystery. A new study published in Nature may offer a crucial answer.

Instead of attempting to directly activate amino acids under simulated primordial conditions—a strategy that has often yielded unstable results—researchers from University College London explored the role of an energy-rich molecule called pantetheine thioester, believed to have formed naturally in early Earth environments such as lakes.

The team found that in aqueous conditions, pantetheine thioester enabled amino acids to bind efficiently to RNA. Remarkably, double-stranded RNA showed high specificity in generating "aminoacyl-RNA" complexes, closely resembling products formed by modern enzymatic processes and avoiding random attachments.

When additional compounds common on the early Earth, such as hydrogen sulfide and thioacids, were introduced, the system successfully linked amino acids into peptide chains—entirely without enzymes or ribosomes.

Although the resulting peptides were random in sequence, some RNA strands displayed preferences for binding specific amino acids, hinting at the earliest emergence of a genetic code.

This work not only strengthens the "RNA world" hypothesis by demonstrating RNA's central role in primitive peptide synthesis, but also bridges it with "metabolism-first" theories, showing how small energy-rich molecules could have driven essential biochemical reactions even before the genetic system fully evolved—laying a chemical foundation for the origin of life.