Exploring a Model for the Primordial RNA Replicase Based on the Ribosome

University Of Southern California, Los Angeles CA

Investigators

Abstract

It is widely believed that a biological system centered on RNA or RNA-like biopolymer, preceded the DNA-, RNA-, and protein-containing system that now dominates. However, this "RNA world" is now disjointed from modern biochemistry and current understanding does not make clear how it could have given rise to the present world through a continuous set of evolutionary steps. The purpose of this research is to explore the hypothesis that the modern ribosome is a molecular fossil of the primordial RNA replicase. In a broader sense, the research aims to address the transition from a hypothetical RNA organism to the Last Universal Common Ancestor (LUCA). To do this, the research group of the Principal Investigator will explore whether the ribosome that currently performs carbon-centered amide and ester bond formation can also perform phosphate-centered transesterification reactions indicative of ribozyme-like chemistry in the same active site. The research group will also investigate the structural plausibility of adaptor-mediated replication in the context of the modern translation apparatus rather than the template-directed replication model that has dominated since the early work of Watson and Crick. The broader impact of this project lies in its effort to enhance both university and pre-university science education related to the themes of the research, through formal coursework, mentoring, and science demonstrations.