Aminoacyl-tRNA Synthetase Function and Mechanisms

Aminoacyl-tRNA synthetases (ARSs) are essential enzymes that catalyse the esterification of amino acids to their cognate transfer RNAs (tRNAs), forming aminoacyl-tRNAs that deliver activated amino acids to the ribosome for protein synthesis. These enzymes are divided into two structural classes and employ conserved catalytic motifs, such as the HIGH and KMSKS sequences in class I ARSs, to bind substrates and stabilise the aminoacyl-adenylate intermediate. To safeguard translational fidelity, many ARSs contain editing domains that remove misactivated or mischarged amino acids before or after transfer to tRNA. Beyond their canonical role, ARSs participate in diverse cellular processes including signal transduction, immune regulation and metabolic homeostasis, often through incorporation into multi-tRNA synthetase complexes or via post-translational modifications. Structural studies have revealed conformational dynamics that underlie substrate specificity and proofreading, while biochemical analyses have elucidated molecular rules—the so-called tRNA identity elements—that guide accurate tRNA recognition. The dual capacity of ARSs for catalysis and regulation has made them attractive targets for antibiotic and antiparasitic drug development, as well as for the design of novel therapeutics addressing human diseases linked to ARS mutations or dysregulation.

Research from Nature Portfolio

Recent structural work has unveiled how specific mutations in the HIGH motif of isoleucyl-tRNA synthetase (IleRS) confer up to a 10^3-fold increase in resistance to the antibiotic mupirocin by reshaping the active site to prevent inhibitor binding while retaining catalytic efficiency. Complementary studies on threonyl-tRNA synthetase (ThrRS) have shown that the natural product borrelidin occupies four distinct subsites within the enzyme’s catalytic domain—blocking the amino acid, ATP and tRNA binding sites and an additional orthogonal pocket—thus providing a quadrivalent mechanism to inhibit protein synthesis in bacteria and eukaryotes. These insights not only deepen understanding of ARS catalysis and inhibition but also inform the rational design of next-generation antimicrobial agents.

Aminoacyl-tRNA Synthetase Function and Mechanisms publication trend

The graph below shows the total number of articles in aminoacyl-trna synthetase function and mechanisms across all publications each year (not limited to Nature Index journals).

Technical terms

Aminoacylation: The enzymatic attachment of an amino acid to the 3′ end of its cognate tRNA, forming an aminoacyl-tRNA.

Editing domain: A specialised region in some ARSs that hydrolyses misactivated amino acids or removes mischarged amino acids from tRNA to maintain translational fidelity.

HIGH motif: A conserved sequence of amino acids (His-Ile-Gly-His) found in class I ARSs that contributes to substrate binding and catalysis.

tRNA identity elements: Specific nucleotide sequences or structural features within tRNA molecules that enable accurate recognition by their corresponding synthetases.

Adenylate intermediate: A high-energy complex of an amino acid and adenosine monophosphate formed transiently during the aminoacylation reaction.

Multi-tRNA synthetase complex (MSC): A multi-enzyme assembly comprising several ARSs and associated factors that functions in translation and non-canonical signalling roles.

References

1. Antibiotic hyper-resistance in a class I aminoacyl-tRNA synthetase with altered active site signature motif. Nature Communications (2023).
2. Structural basis for full-spectrum inhibition of translational functions on a tRNA synthetase. Nature Communications (2015).
3. The tRNA identity landscape for aminoacylation and beyond. Nucleic Acids Research (2023).
4. Phosphocode-dependent glutamyl-prolyl-tRNA synthetase 1 signaling in immunity, metabolism, and disease. Experimental & Molecular Medicine (2023).
5. Aminoacyl‐tRNA synthetases in medicine and disease. EMBO Molecular Medicine (2013).