Experimental Kinetic Study to Explore the Impact of Macromolecular Crowding on Structure and Function of Escherichia coli Prolyl–tRNA Synthetase

Abstract

Aminoacyl-tRNA synthetases (AARSs) are enzymes that catalyze the covalent attachment of amino acids to their cognate tRNA. This reaction is known as aminoacylation of tRNA and is crucial for protein synthesis in all living organisms. These essential enzymes are large proteins, comprised of multiple domains. It has been proposed that the coupled dynamics between various structural elements of these enzymes are responsible for facilitating enzymatic rate enhancement. Unfortunately, previous in vitro studies were limited to dilute solution environments, and were unable to account for the impact of the macromolecular crowding in the cellular environment on these coupled dynamics. We are employing an experimental, non-radioactive enzyme kinetics approach, to probe the impact of macro molecular crowding agents such as sucrose, dextran, and ficoll-70 on the structure, dynamics, and function of Escherichia coli prolyl-tRNA synthetase. The preliminary data of our comparative study in the absence and presence of crowding agents will be presented.