Aminoacyl-tRNA Synthetases in the Bacterial World

Area of Science:

• Biochemistry and Molecular Biology
• Genetics and Genomics
• Evolutionary Biology

Background:

• Aminoacyl-tRNAsynthetases (aaRSs) are universally conserved enzymes crucial for accurate protein synthesis by attaching amino acids to tRNAs.
• Beyond translation, certain aaRSs have evolved additional functions, highlighting their versatility.
• Significant structural and regulatory diversity exists among aaRSs across different life kingdoms and species.

Purpose of the Study:

• To provide a comprehensive review of bacterial aminoacyl-tRNAsynthetases (aaRSs) and their paralogs.
• To explore the structure, function, regulation, and evolution of these enzymes, with an emphasis on structure-function relationships.
• To highlight the alternative functions of aaRSs and their paralogs in various cellular processes.

Main Methods:

• Review of extensive genomic and structural data accumulated over the past two decades.
• Analysis of enzyme mechanisms, including tRNA aminoacylation and error-correction editing.
• Comparative analysis of aaRSs across bacteria, archaea, and eukaryotes, including organelle-specific synthetases.

Main Results:

• Bacterial aaRSs exhibit considerable structural diversity (oligomerization, modularity, additional domains) and functional plasticity.
• Mechanisms of gene regulation for aaRSs are not conserved and vary significantly between bacterial groups.
• aaRSs and their paralogs participate in diverse cellular processes, including cell wall biogenesis and other metabolic pathways.
• Comparative analysis reveals both conserved and distinct features of aaRSs across the three domains of life.

Conclusions:

• Bacterial aaRSs are highly adaptable enzymes with diverse structures, functions, and regulatory mechanisms.
• Understanding aaRS diversity and alternative functions provides insights into their evolutionary history and roles beyond translation.
• The field has advanced from reductionist approaches to more integrated studies of aaRSs, driven by accumulated genomic and structural data.