Scientists find primordial protein fragments that existed billions of years ago

Utilizing a technique similar to that used to reconstruct ancient vocabularies by comparing them to modern languages, researchers from the Max Planck Institute for Developmental Biology have identified primordial protein fragments that existed billion of years ago.

As they explained in a recent issue of the journal eLife, Andrei Lupas, director of the Department of Protein Evolution at the Institute, and his colleagues were able to reconstruct 40 ancient pieces of peptides by using computational methods to compare them to modern-day proteins.

These peptidic fragments may represent the observable remains of the time during which the first proteins were created—which would have occurred more than 3.5 billon years ago. Their findings may shed new light on how the building blocks of all life originally came into existence.

Research could lead to designer proteins, researchers claim

“Life,” Lupas explained Monday in a statement, “can be viewed as substantially resulting from the chemical activity of proteins.” Proteins are the basic building blocks of all living things, from people on down to microbes. In humans, they form our hair, nails, bones, and muscles, defend us from pathogens and even help digest the food we consume, the authors said.

But how did they come to be in the first place? Scientists known that proteins are comprised of thousands of modular units called domains assembled together, yet the origin of these fragments themselves remain uncertain. The researchers set out to investigate on hypothesis: that the first of these domains arose by fusion from an ancient set of simple peptides.

During their analysis, Lupas and his fellow investigators identified 40 peptidic fragments which occur in proteins that do not appear to be related, but which are strikingly similar in structure and sequences. These fragments were abundant in the most ancient types of proteins and were found to be involved with base RNA and DNA-binding functions, leading the study authors to suggest that they are remnants from a world that predates the existence of DNA-based life.

The researchers believe that future studies will need to examine the role these fragments play in the formation of protein structures, and that the results could ultimately help lead to the creation of new forms of protein, as well as the enhancement of existing ones.

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Feature Image: MPI for Developmental Biology/ Vikram Alva