Optimizing frameshift suppressor tRNAs for the recoding of the genetic code

Emory University, Atlanta GA

Investigators

Abstract

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Christine Dunham from Emory University to investigate mechanisms to control protein expression with the goal of engineering proteins with diverse, non-natural chemical moieties. The translational machinery of cells is responsible for the incorporation in proteins of twenty-two amino acids. For research and application purposes, the incorporation of non-naturally occurring amino acids is very important and has long been recognized as an important goal of synthetic biology. This represents a current technological challenge. The research in Dr. Dunham's lab develops a solution to this challenge that is based on the use of engineered molecules called transfer RNA (tRNAs). The research in her lab is a training ground for graduate students and postdoctoral fellows, who acquire interdisciplinary scientific skills at the interface between biology and chemistry. This project is also integrated into an outreach program whose mission is to raise the interest of high school students in STEM, to train these students to become independent thinkers, and to help create a diverse STEM workforce. The question of how to manipulate the ribosome to express proteins containing one or more novel chemical moieties is an important synthetic biology puzzle. The realization that the genetic code is not immutable and that recoding events could occur has attracted the interest of many chemical biologists. The major limitations of previous approaches to solve this puzzle include cross-reactivity with host translation machinery and low incorporation of engineered molecules on the ribosome due to competition with endogenous tRNAs. This proposal centers on expanding the coding capacity of tRNAs using the novel and innovative strategy of rational, structure-based redesign of frameshift suppressor tRNAs and biochemical and structural biology approaches. Information from this study provides new insights into the regulation of protein synthesis, a topic critically important to a broad biomolecular and synthetic biology research community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.