Washington: Researchers have now offered an intriguing new view about how life began on Earth.
University of North Carolina at Chapel Hill School of Medicine biochemist Charles Carter, PhD, and his team recreated ancient protein enzymes that likely played a vital role in helping create life on Earth.
The research team created and superimposed digital three-dimensional versions of the two super-families to see how their structures aligned.
Carter found that all the enzymes have virtually identical cores that can be extracted to produce `molecular fossils` he calls Urzymes - Ur meaning earliest or original. The other parts, he said, are variations that were introduced later, as evolution unfolded.
These two Urzymes are as close as scientists have gotten to the actual ancient enzymes that would have populated the Earth billions of years ago.
Both Urzymes are very good at accelerating the two reactions necessary to translate the genetic code.
The finding also suggests that Urzymes evolved from even simpler ancestors - tiny proteins called peptides. And over time those peptides co-evolved with RNA to give rise to more complex life forms.
In this `Peptide-RNA World` scenario, RNA would have contained the instructions for life while peptides would have accelerated key chemical reactions to carry out those instructions.
The study has been published in the Journal of Biological Chemistry.