Chemical footprinting and kinetic assays reveal dual functions for highly conserved eukaryotic tRNA^His guanylyltransferase residues.

ABSTRACT: tRNA^His guanylyltransferase (Thg1) adds a single guanine to the -1 position of tRNA^His as part of its maturation. This seemingly modest addition of one nucleotide to tRNA^His ensures translational fidelity by providing a critical identity element for the histidyl aminoacyl tRNA synthetase (HisRS). Like HisRS, Thg1 utilizes the GUG anticodon for selective tRNA^His recognition, and Thg1-tRNA complex structures have revealed conserved residues that interact with anticodon nucleotides. Separately, kinetic analysis of alanine variants has demonstrated that many of these same residues are required for catalytic activity. A model in which loss of activity with the variants was attributed directly to loss of the critical anticodon interaction has been prop

SUBMITTER: Matlock AO 

PROVIDER: S-EPMC6552426 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature