Structure and Dynamics of tRNA Met ContainingCore Substitutions

The fidelity of protein synthesis is largely dominated by the accurate recognition of transfer RNAs (tRNAs) by their cognate aminoacyl-tRNA synthetases. Aminoacylation of each tRNA with its cognate amino acid is necessary to maintain the accuracy of genetic code input. Aminoacylated tRNAMet functions in both initiation and elongation steps during protein synthesis. As a precursor to the investigation of a methionyl-tRNA synthetase–tRNAMet complex, presented here are the results of molecular dynamics (MD) for single nucleotide substitutions in the D-loop of tRNAMet (G15A, G18A, and G19A) probing structure/function relationships. The core of tRNAMet likely mediates an effective communication between the tRNA anticodon and acceptor ends, contributing an acceptor stem rearrangement to fit into the enzyme-active site. Simulations of Escherichia coli tRNAMet were performed for 1 μs four times each. The MD simulations showed changes in tRNA flexibility and long-range communication most prominently in the G18A va...