Boyarshin K. Structural and functional basis of the editing activity of prolil-tRNA synthetase from Enterococcus faecalis

The thesis is devoted to the editing mechanisms of prokaryotic type prolyl-tRNA synthetase. The first time tRNA-dependence of the velocity of alanyl-adenylate hydrolysis by ProRS known as the pretransfer editing. The necessity of 2'- and 3'-hydroxyl groups of A76 tRNAPro to accelerate the hydrolysis of alanyl-adenylate was found. Amino acid residues that ensure the efficiency of alanyl-tRNAPro hydrolysis were identified. The key role of the 2'-hydroxyl group of alanyl-tRNAPro A76 in the deacylation reaction was discovered. Comparison of experimental data with results of computer simulations allowed to confirm the quantum-mechanical model of alanyl-tRNAPro substrate-assisted catalytic hydrolysis. Comparision of the alanyl-tRNAPro hydrolysis catalytical mechanism with other proposed mechanisms of aminoacyl-tRNA catalytical hydrolysis allowed to emphasize the importance of the Intramolecular interactions in the substrate molecule.