Novel Mutants of EF-Tu

  • Diarmaid Hughes
  • C. G. Kurland


The process of translation in bacteria is familiar in its broad outlines. However precise knowledge of many of its reactions, their kinetics and the strategies underlying them is still lacking. During the elongation cycle, EF-Tu, in a ternary complex with GTP and aminoacyl-tRNA, plays a role in mediating the interaction between the aminoacyl-tRNA and the ribosome. The elongation cycle in bacteria such as E.coli operates at a rate of up to 20 amino acids per second and with an error frequency in the range of 10–3- 10–4 per codon. How EF-Tu contributes to this level of efficiency is unclear. We are studying wild-type and mutant derivatives of EF-Tu in an attempt to define in more detail the elongation cycle and the role of ternary complex in translation. The cycle of elongation may be formally considered to comprise two stages; the selection of a correct aminoacyl-tRNA on a codon-programmed ribosome, and the selection of a new codon involving movement of the selected tRNA relative to the ribosome. The selection of the correct aminoacyl-tRNA species involves a reversible initial selection (I) followed by hydrolysis of GTP on the ternary complex. The low accuracy of this initial selection is increased by one or more kinetic proofreading steps (F) resulting either in the successful formation of a peptide bond or the ejection of the aminoacyl-tRNA from the ribosome (Thompson and Stone, 1977; Ruusala et al, 1982).


Ternary Complex Frameshift Mutation Initial Selection Mutant Derivative Elongation Cycle 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Andersson, D.I., van Verseveld, H.W., Stouthamer, A.H. and Kurland, C.G., 1986, Suboptimal growth with hyperaccurate ribosomes, Arch. Microbiol., 144:96.PubMedCrossRefGoogle Scholar
  2. Ehrenberg, M., Kurland, C.G. and Ruusala, T., 1986, Counting cycles of EF-Tu to measure proofreading in translation, Biochemie, 68:261.CrossRefGoogle Scholar
  3. Hopfield, J.J., 1974, Kinetic proofreading: a new mechanism for reducing errors in biosynthetic processes requiring high specificity, Proc. Nat. Acad. Sci. USA, 71:4135.PubMedCrossRefGoogle Scholar
  4. Hughes, D., 1984, External suppression of +1 and -1 frameshift mutations: a genetic analysis in bacteria, Ph.D. Thesis, Dublin University.Google Scholar
  5. Hughes, D., 1986, The isolation and mapping of EF-Tu mutations in Salmonella typhimurium, Mol. Gen. Genet., 202:108.PubMedCrossRefGoogle Scholar
  6. Hughes, D., 1987, Mutant forms of tufA and tufB independently suppress nonsense mutations, J. Mol. Biol., 197:611.PubMedCrossRefGoogle Scholar
  7. Hughes, D., Atkins, J.F. and Thompson, S., 1987, Mutants of elongation factor Tu promote ribosomal frameshifting and nonsense readthrough, EMBO J., 6:4235.PubMedGoogle Scholar
  8. Kurland, C.G., 1979, Reading frame errors on ribosomes, in: ‘Nonsense mutations and tRNA suppressors,’ J.E. Cells and J.D. Smith, eds., Academic press, New York.Google Scholar
  9. Ninio, J., 1975, Kinetic amplification of enzyme discrimination, Biochemie, 57:587.CrossRefGoogle Scholar
  10. Ruusala, T., Ehrenberg, M., and Kurland, C.G., 1982, Is there proofreading during polypeptide synthesis?, EMBO J., 1:741.PubMedGoogle Scholar
  11. Thompson, R.C. and Stone, P.J., 1977, Proofreading of the codon-anticodon interaction on ribosomes, Proc. Nat. Acad. Sci. USA, 74:198.PubMedCrossRefGoogle Scholar
  12. Vijgenboom, E. and Bosch, L., 1987, Transfer of plasmid-borne tuf mutations to the chromosome as a genetic tool for studying the functioning of EF-TuA and EF-TuB in the E.coli cell, Biochemie, 69:1021.Google Scholar
  13. Wagner, E.G.H., Jelenc, P.C., Ehrenberg, M., and Kurland, C.G., 1982, Rate of elongation of polyphenylalanine in vitro, Eur. J. Biochem., 122:193PubMedCrossRefGoogle Scholar
  14. Wolf, H., Chinali, G. and Parmeggiani, A., 1977, Mechanism of inhibition of of protein biosynthesis bi kirromycin, Eur. J. Biochem., 75:67.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1989

Authors and Affiliations

  • Diarmaid Hughes
    • 1
  • C. G. Kurland
    • 1
  1. 1.Department of Molecular BiologyThe Biomedical CenterUppsalaSweden

Personalised recommendations