Origin of the genetic code: First aminoacyl-tRNA synthetases could replace isofunctional ribozymes when only the second base of codons was established

Sergei N. Rodin, Andrei S. Rodin

Research output: Contribution to journalArticle

23 Citations (Scopus)


Analysis of the updated compilation of more than 8000 tRNA gene sequences confirmed our previously reported finding that in pairs of consensus tRNAs with complementary anticodons, their second bases in the acceptor stems are also complementary. This dual complementarity points to the following: (1) the operational code embodied in the acceptor stem, and the classic genetic code embodied in the anticodon could have had the same common ancestor; (2) new tRNAs most likely entered primitive translation in pairs with complementary anticodons; and (3) this process of code expansion was directed by the primordial double-strand coding. However, we did not find the dual complementarity when testing all tRNA pairs in which anticodons were complementary only at the central position, but not complementary at least at one of the flanking two positions. This observation, together with certain additional evidence, suggests that both codes were still being shaped (with only the second base established at the time) when the first protein aminoacyl-tRNA synthetases could have already started replacing their ribozymic precursors.

Original languageEnglish
Pages (from-to)365-375
Number of pages11
JournalDNA and Cell Biology
Issue number6
Publication statusPublished - Jun 1 2006


ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cell Biology

Cite this