Archaeal aminoacyl-tRNA synthetases interact with the ribosome to recycle tRNAs

Nucleic Acids Res. 2014 Apr;42(8):5191-201. doi: 10.1093/nar/gku164. Epub 2014 Feb 24.


Aminoacyl-tRNA synthetases (aaRS) are essential enzymes catalyzing the formation of aminoacyl-tRNAs, the immediate precursors for encoded peptides in ribosomal protein synthesis. Previous studies have suggested a link between tRNA aminoacylation and high-molecular-weight cellular complexes such as the cytoskeleton or ribosomes. However, the structural basis of these interactions and potential mechanistic implications are not well understood. To biochemically characterize these interactions we have used a system of two interacting archaeal aaRSs: an atypical methanogenic-type seryl-tRNA synthetase and an archaeal ArgRS. More specifically, we have shown by thermophoresis and surface plasmon resonance that these two aaRSs bind to the large ribosomal subunit with micromolar affinities. We have identified the L7/L12 stalk and the proteins located near the stalk base as the main sites for aaRS binding. Finally, we have performed a bioinformatics analysis of synonymous codons in the Methanothermobacter thermautotrophicus genome that supports a mechanism in which the deacylated tRNAs may be recharged by aaRSs bound to the ribosome and reused at the next occurrence of a codon encoding the same amino acid. These results suggest a mechanism of tRNA recycling in which aaRSs associate with the L7/L12 stalk region to recapture the tRNAs released from the preceding ribosome in polysomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acyl-tRNA Synthetases / metabolism*
  • Archaea / enzymology*
  • Arginine-tRNA Ligase / metabolism
  • Genome, Archaeal
  • Methanobacteriaceae / genetics
  • Protein Biosynthesis*
  • RNA, Transfer / metabolism*
  • Ribosomal Proteins / metabolism
  • Ribosomes / enzymology*
  • Serine-tRNA Ligase / metabolism


  • Ribosomal Proteins
  • RNA, Transfer
  • Amino Acyl-tRNA Synthetases
  • Serine-tRNA Ligase
  • Arginine-tRNA Ligase