No Rosetta stone for a sense-antisense origin of aminoacyl tRNA synthetase classes

Tom A. Williams, Kenneth H. Wolfe, Mario A. Fares

Research output: Contribution to journalArticle (Academic Journal)peer-review

12 Citations (Scopus)


Aminoacyl tRNA synthetases (aaRS) are crucial enzymes that join amino acids to their cognate tRNAs, thereby implementing the genetic code. These enzymes fall into two unrelated structural classes whose evolution has not been explained. The leading hypothesis, proposed by Rodin and Ohno, is that the two classes originated as a pair of sense-antisense genes encoded on opposite strands of a single DNA molecule. This unusual idea obtained its main support from reports of a "Rosetta stone": a locus where genes for heat shock protein 70 (HSP70) and an Nicotinamide adenine dinulecotide-specific glutamate dehydrogenase (NAD-GDH), which are structurally homologous to the two classes of aaRS, overlap extensively on complementary DNA strands. This remarkable locus was first characterized in the oomycete Achlya klebsiana and has since been reported in many other species. Here we present evidence that the open reading frames on the antisense strand of HSP70 genes are spurious, and we identify a more probable candidate for the gene encoding the oomycete NAD-GDH enzyme. These results cast extensive doubt on the Rosetta Stone argument.

Original languageEnglish
Pages (from-to)445-450
Number of pages6
JournalMolecular Biology and Evolution
Issue number2
Publication statusPublished - Feb 2009


  • Aminoacyl tRNA synthetase
  • Hsp70
  • Rosetta stone


Dive into the research topics of 'No Rosetta stone for a sense-antisense origin of aminoacyl tRNA synthetase classes'. Together they form a unique fingerprint.

Cite this