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Biomolecular Concepts

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Alternative genetic code for amino acids and transfer RNA revisited

Kiyofumi Hamashima
  • Institute for Advanced Biosciences, Keio University, 997-0017 Tsuruoka, Japan
  • Systems Biology Program, Graduate School of Media and Governance, Keio University, 252-8520 Fujisawa, Japan
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Akio Kanai
  • Corresponding author
  • Institute for Advanced Biosciences, Keio University, 997-0017 Tsuruoka, Japan
  • Systems Biology Program, Graduate School of Media and Governance, Keio University, 252-8520 Fujisawa, Japan
  • Faculty of Environment and Information Studies, Keio University, 252-8520 Fujisawa, Japan
  • Email
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2013-03-18 | DOI: https://doi.org/10.1515/bmc-2013-0002


The genetic code is highly conserved among all organisms and its evolution is thought to be strictly limited. However, an increasing number of studies have reported non-standard codes in prokaryotic and eukaryotic genomes. Most of these deviations from the standard code are attributable to tRNA changes relating to, for example, codon/anticodon base pairing and tRNA/aminoacyl-tRNA synthetase recognition. In this review, we focus on tRNA, a key molecule in the translation of the genetic code, and summarize the most recently published information on the evolutionary divergence of the tRNAs. Surprisingly, although higher eukaryotes, such as the nematode (worm), utilize the standard genetic code, newly identified nematode-specific tRNAs (nev-tRNAs) translate nucleotides in a manner that transgresses the code. Furthermore, a variety of additional functions of tRNAs, beyond their translation of the genetic code, have emerged rapidly. We also review these intriguing new aspects of tRNA, which have potential impacts on translational control, RNA silencing, antibiotic resistance, RNA biosynthesis, and transcriptional regulation.

Keywords: evolution; genetic code; protein synthesis; transfer RNA; tRNA fragment


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About the article

Corresponding author: Akio Kanai, Institute for Advanced Biosciences, Keio University, 997-0017 Tsuruoka, Japan; Systems Biology Program, Graduate School of Media and Governance, Keio University, 252-8520 Fujisawa, Japan; and Faculty of Environment and Information Studies, Keio University, 252-8520 Fujisawa, Japan

Received: 2013-01-26

Accepted: 2013-02-20

Published Online: 2013-03-18

Published in Print: 2013-06-01

Citation Information: BioMolecular Concepts, ISSN (Online) 1868-503X, ISSN (Print) 1868-5021, DOI: https://doi.org/10.1515/bmc-2013-0002.

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