Skip to main content
Log in

Degeneracy of the information contained in amino acid sequences: Evidence from overlaid genes

  • Published:
Journal of Molecular Evolution Aims and scope Submit manuscript

Summary

The observed gene overlays in the viruses ФX174 and SV40 show a surprising economy of information storage; two different amino acid sequences are read in different frames from the same stretch of DNA. This phenomenon appears contradictory in that the information in the two overlaid amino acid sequences is strongly interdependent, yet each of the two proteins has evolved to its own well-defined function. The contradiction can be resolved by assuming sufficiently large degeneracy of the information contents of amino acid sequences with respect to function. Such a degeneracy is familiar from homologous proteins where a given biological function is implemented by many different amino acid sequences. It is shown that the very existence of viral overlays allows to derive a lower limit for the magnitude of this degeneracy: The degeneracy is equal to, or greater than fourfold; on the average, at each position of the chain a choice of 1 out of 5 or less amino acids, and not a choice of 1 out of 20 is necessary for constructing a protein with a specified function. In addition, the strong dependence of overlay probabilities on chain length allows the definition of a maximal length of overlays; in bacterial viruses overlay regions should be shorter than about 150 residues.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Dayhoff, M.O. (1972). Atlas of Protein Sequence and Structure, Vol.5, Silver Spring: Natl. Biomed. Res. Found.

    Google Scholar 

  • Durham, A. (1978). New Scientist77, 785–787

    Google Scholar 

  • Fiers, W., Contreras, R., Haegeman, G., Rogiers, R., Van der Voorde, A., Van Heuverswyn, H., Van Herreweghe, J., Volckaert, G., Ysebaert, M. (1978). Nature273, 113–120

    Google Scholar 

  • Reddy, V B., Thimmappaya, B., Dhar, R., Subramanian, K.N., Zain, B.S., Pan, J., Ghosh, P.K., Celma, M.L., Weissman, S.M. (1978). Science200, 494–502

    Google Scholar 

  • Sanger, F., Air, G.M., Barrell, B.G., Brown, N.L., Coulson, A.R., Fiddes, J.C., Hutchinson, II, C.A., Slocombe, P.M., Smith, M. (1977). Nature265, 687–695

    Google Scholar 

  • Shaw, D.C., Walker, J.E., Northrop, F.D., Barrell, B.G., Godson, G.N., Fiddes, J.C. (1978). Nature272, 510–515

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Sander, C., Schulz, G.E. Degeneracy of the information contained in amino acid sequences: Evidence from overlaid genes. J Mol Evol 13, 245–252 (1979). https://doi.org/10.1007/BF01739483

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01739483

Key words

Navigation