Metabolism of D-aminoacyl-tRNAs in Escherichia coli and Saccharomyces cerevisiae cells

J Biol Chem. 2000 Oct 20;275(42):32535-42. doi: 10.1074/jbc.M005166200.


In Escherichia coli, tyrosyl-tRNA synthetase is known to esterify tRNA(Tyr) with tyrosine. Resulting d-Tyr-tRNA(Tyr) can be hydrolyzed by a d-Tyr-tRNA(Tyr) deacylase. By monitoring E. coli growth in liquid medium, we systematically searched for other d-amino acids, the toxicity of which might be exacerbated by the inactivation of the gene encoding d-Tyr-tRNA(Tyr) deacylase. In addition to the already documented case of d-tyrosine, positive responses were obtained with d-tryptophan, d-aspartate, d-serine, and d-glutamine. In agreement with this observation, production of d-Asp-tRNA(Asp) and d-Trp-tRNA(Trp) by aspartyl-tRNA synthetase and tryptophanyl-tRNA synthetase, respectively, was established in vitro. Furthermore, the two d-aminoacylated tRNAs behaved as substrates of purified E. coli d-Tyr-tRNA(Tyr) deacylase. These results indicate that an unexpected high number of d-amino acids can impair the bacterium growth through the accumulation of d-aminoacyl-tRNA molecules and that d-Tyr-tRNA(Tyr) deacylase has a specificity broad enough to recycle any of these molecules. The same strategy of screening was applied using Saccharomyces cerevisiae, the tyrosyl-tRNA synthetase of which also produces d-Tyr-tRNA(Tyr), and which, like E. coli, possesses a d-Tyr-tRNA(Tyr) deacylase activity. In this case, inhibition of growth by the various 19 d-amino acids was followed on solid medium. Two isogenic strains containing or not the deacylase were compared. Toxic effects of d-tyrosine and d-leucine were reinforced upon deprivation of the deacylase. This observation suggests that, in yeast, at least two d-amino acids succeed in being transferred onto tRNAs and that, like in E. coli, the resulting two d-aminoacyl-tRNAs are substrates of a same d-aminoacyl-tRNA deacylase.

MeSH terms

  • Amino Acyl-tRNA Synthetases / metabolism*
  • Aspartate-tRNA Ligase / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Escherichia coli / metabolism
  • Genotype
  • Plasmids
  • RNA, Transfer, Amino Acid-Specific / metabolism*
  • RNA, Transfer, Asp / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Stereoisomerism
  • Substrate Specificity
  • Tryptophan / metabolism*
  • Tryptophan-tRNA Ligase / metabolism*
  • Tyrosine-tRNA Ligase / metabolism*


  • RNA, Transfer, Amino Acid-Specific
  • RNA, Transfer, Asp
  • Tryptophan
  • Amino Acyl-tRNA Synthetases
  • Tyrosine-tRNA Ligase
  • Aspartate-tRNA Ligase
  • Tryptophan-tRNA Ligase