Really interesting work. Essentially shows that stacking interactions and hydrogen bonding of the nitrogenous bases is sufficient to form a “proto-RNA” filament. While far from being definitive proof of anything, this work certainly builds on and supports the RNA-world hypothesis for the origins of life. Very cool stuff, will update this post when more information becomes available.
Excerpt from “Molecules assemble in water, hint at origins of life” in e! Science News
Researchers at the Georgia Institute of Technology are exploring an alternate theory for the origin of RNA: they think the RNA bases may have evolved from a pair of molecules distinct from the bases we have today. This theory looks increasingly attractive, as the Georgia Tech group was able to achieve efficient, highly ordered self-assembly in water with small molecules that are similar to the bases of RNA. These “proto-RNA bases” spontaneously assemble into gene-length linear stacks, suggesting that the genes of life could have gotten started from these or similar molecules.
The discovery was made by a team of scientists led by Georgia Tech Professor Nicholas Hud, who has been trying for years to find simple molecules that will assemble in water and be capable of forming RNA or its ancestor. Hud’s group knew that they were on to something when they added a small chemical tail to a proto-RNA base and saw it spontaneously form linear assemblies with another proto-RNA base. In some cases, the results produced 18,000 nicely ordered, stacked molecules in one long structure.
Hud concedes that scientists may never be 100 percent sure what existed four billion years ago when a complex mixture of chemicals started to work together to start life. His next goal is to determine whether the proto-RNA bases can be linked by a backbone to form a polymer that could have functioned as a genetic material.
RNA on Steroids
2 pm Friday, 5/25, LS1022.
Dr Loren Williams, Director, NASA Center for Ribosomal Evolution and Adaptation, GA Tech, Atlanta
Dr Williams works on rewinding the “tape of life”: to shed light on the nature of protein synthesis prior to the last universal common ancestor of life. His center focuses on the characteristics of ancient macromolecules and their assemblies, specifically on aboriginal mechanisms of peptide synthesis by RNA – an attempt to uncover clues about key steps in the transition from the RNA world to the protein. In part, Dr Williams work carries the potential of discovering and characterizing the oldest traceable macromolecules and machines of life, and the earliest discernable connection between RNA and protein. The formation of the Peptidyl Transferase Center marked the beginning of the translation machinery and the beginning of the end of the RNA world. Therefore, working on the resurrection and the structures of ancestral Peptidyl Transferase Centers allows Dr Williams to test ideas about primitive living systems, as well as the origin of protein.