Nature 325, 728 - 730 (19 February 1987); doi:10.1038/325728a0

Coevolution of codon usage and transfer RNA abundance

Michael Bulmer

Department of Biomathematics, University of Oxford, 5 South Parks Road, Oxford OX1 3UB, UK

The use of synonymous codons is strongly biased in the bacterium Escherichia coli and yeast, comprising both bias between codons recognized by the same transfer RNA and bias between groups of codons recognized by different synonymous tRNAs (reviewed in ref. 1). A major determinant of the second sort of bias is tRNA content, codons recognized by abundant tRNAs being used more often than those recognised by rare tRNAs, particularly in highly expressed genes, probably owing to selection at the level of translation against codons recognized by rare tRNAs^1–3. Conversely, codon usage is likely to exert selection pressure on tRNA abundance⁴. Here I develop a model for the coevolution of codon usage and tRNA abundance which explains why there are unequal abundances of synonymous tRNAs leading to biased usage between groups of codons recognized by them in unicellular organisms.

References

1.	Ikemura, T. Mol. Biol. Evol. 2, 13−34 (1985). | PubMed | ISI | ChemPort |
2.	Post, L. E., Strycharz, G. D., Nomura, M., Lewis, H. & Dennis, P. P. Proc. natn. Acad. Sci. U.S.A. 76, 1697−1701 (1979). | ChemPort |
3.	Bennetzen, J. L. & Hall, B. D. J. biol. Chem. 257, 3026−3031 (1982). | PubMed | ISI | ChemPort |
4.	Kimura, M. The Neutral Theory of Molecular Evolution (Cambridge University Press, Cambridge, 1983).
5.	Sharp, P. M. & Li, W-H. J. molec. Evol. (in the press).
6.	Varenne, S., Buc, J., Lloubes, R. & Lazdunski, C. J. molec. Biol. 180, 549−576 (1984). | Article | PubMed | ChemPort |
7.	Pedersen, S. EMBO J. 3, 2895−2898 (1984). | PubMed | ISI | ChemPort |
8.	Robinson, M. et al. Nucleic Acids Res. 12, 6663−6671 (1984). | PubMed | ISI | ChemPort |
9.	Bonekamp, F., Andersen, H. D., Christensen, T. & Jensen, K. F. Nucleic Acids Res. 13, 4113−4123. | PubMed | ChemPort |
10.	Gouy, M. & Grantham, R. FEBS Lett. 115, 151−155 (1980). | Article | PubMed | ChemPort |
11.	Lipman, D. J. & Wilbur, W. J. J. molec. Biol. 163, 363−376 (1983). | Article | PubMed | ChemPort |
12.	Li, W-H. J. molec. Evol. (in the press).