Yajun Wang, Ph.D.

Education: University of British Columbia, Ph.D., Nucleic Acid Chemistry
Institution: University of California, Irvine (laboratory of John Chaput)

SCOL Project: Evaluating TNA as a Pre-RNA World Catalyst

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are nature’s solution to the problem of how to store and transfer genetic information between members of the same species. In addition, certain RNAs are also able to catalyze reactions that involve such complex chemistry as RNA processing and protein synthesis. RNA’s ability to be a genetic material and biocatalyst led to the RNA world hypothesis, which suggests that modern life evolved from RNA-based life forms in which RNA stored genetic information and catalyzed chemical reactions. Despite the importance of RNA in modern biology, it is not clear if RNA was the first genetic material of life or an evolutionary intermediate that gave rise to modern life.

One could imagine that whatever chemistry gave rise to RNA would have produced other RNA analogs, some of which could have competed with or possibly even preceded RNA in the evolution of life. One interesting candidate for an RNA progenitor is threose nucleic acid (TNA), which is able to exchange information with RNA by forming complementary A-T and G-C pairs in a Watson–Crick double helix. Demonstrating that TNA can catalyze chemical reactions in the same way as RNA would help advance the theory that TNA is a viable RNA world progenitor. This project will use Darwinian evolution methods to evolve a TNA enzyme for a chemical reaction, so a direct comparison can be made between the functional properties of RNA and TNA.