Trans-complementable copy-number mutants of plasmid ColE1 (original) (raw)

Nature volume 283, pages 216–218 (1980)Cite this article

Abstract

Plasmid ColE1, like many other small non-conjugative plasmids, is present in multiple copies (about 15 per chromsome equivalent) in Escherichia coli cells1,2. Because of their high copy number, the replication of such plasmids has been described as ‘relaxed’, even though there is good evidence that it is strictly controlled: ColE1 derivatives have characteristic but different copy numbers2 and ColE1 copy-number mutants have been characterised3–5. No plasmid-specified protein is essential for the replication of ColE1 and related plasmids, as extensive replication can occur in chloramphenicol-treated cells6, in plasmid-free chloramphenicol-treated cells transfected with a hybrid ColE1/phage replicon and in vitro in extracts derived from plasmid-free cells8. Nevertheless, it is possible that a plasmid-specified protein is involved in ColE1 replication control in viable cells. Here we show that deletion of a given non-essential region from ColE1-like plasmids results in a raised copy number. Such plasmids are stably maintained and have their copy number returned to normal when a complementing plasmid is present in the same cell, indicating that a plasmid-specified diffusible gene product regulates the plasmid content of ColE1-containing cells. Deletion of the equivalent region from the cloning vector pBR322 gives a derivative which has a raised copy number and which has also lost its origin for conjugal transfer; unlike pBR322, it cannot be mobilised.

This is a preview of subscription content, access via your institution

Access options

Subscribe to this journal

Receive 51 print issues and online access

$199.00 per year

only $3.90 per issue

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Additional access options:

Similar content being viewed by others

References

  1. Bazaral, M. & Helinski, D. R. Biochemistry 10, 3513–3519 (1968).
    Article Google Scholar
  2. Staudenbauer, W. L. Curr. Topics Microbiol. Immun. 83, 93–156 (1978).
    CAS Google Scholar
  3. Gelfand, D. H., Shepard, H. M., O'Farrell, P. H. & Polisky, B. Proc. natn. Acad. Sci. U.S.A. 75, 5869–5873 (1978).
    Article ADS CAS Google Scholar
  4. Heffron, F., So, M. & McCarthy, B. J. Proc. natn. Acad. Sci. U.S.A. 75, 6012–6016 (1978).
    Article ADS CAS Google Scholar
  5. Conrad, S. E. & Campbell, J. L. Cell 18, 61–71 (1979).
    Article CAS Google Scholar
  6. Clewell, D. B. J. Bact. 110, 667–676 (1972).
    CAS PubMed Google Scholar
  7. Kahn, M. & Helinski, D. R. Proc. natn. Acad. Sci. U.S.A. 75, 2200–2204 (1978).
    Article ADS CAS Google Scholar
  8. Tomizawa, J., Sakakibara, Y. & Kakefuda, T. Proc. natn. Acad. Sci. U.S.A. 72, 1050–1054 (1975).
    Article ADS CAS Google Scholar
  9. Chang, A. C. Y. & Cohen, S. N. J. Bact. 134, 1141–1156 (1978).
    CAS PubMed Google Scholar
  10. Dougan, G. & Sherratt, D. J. Molec. gen. Genet. 151, 151–160 (1977).
    Article CAS Google Scholar
  11. Warren, G. & Sherratt, D. J. Molec. gen. Genet. 151, 197–201 (1977).
    Article CAS Google Scholar
  12. Bolivar, F. et al. Gene 2, 95–113 (1977).
    Article CAS Google Scholar
  13. Sutcliffe, J. G. Cold Spring Harb. Symp. quant. Biol. 43, 77–90 (1978).
    Article Google Scholar
  14. Rodriguez, R. L., Bolivar, F., Goodman, H. M., Boyer, H. W. & Betlach, M. in ICN–UCLA Symp. molec. cell. Biol. Vol. 5 (eds Nierlich, D. P., Rutter, W. J. & Fox, C. F.) 471–477 (Academic, New York, 1976).
    Google Scholar
  15. Warren, G. J., Twigg, A. J. & Sherratt, D. J. Nature 274, 259–261 (1978).
    Article ADS CAS Google Scholar
  16. Warren, G. J. & Sherratt, D. J. Molec. gen. Genet. 161, 39–47 (1978).
    Article CAS Google Scholar
  17. Bedbrook, J. R., Lehrach, H. & Ausubel, F. M. Nature 281, 447–452 (1979).
    Article ADS CAS Google Scholar

Download references

Author information

Authors and Affiliations

  1. School of Biological Sciences, University of Sussex, Falmer, Brighton, UK
    Andrea J. Twigg & David Sherratt

Authors

  1. Andrea J. Twigg
    You can also search for this author inPubMed Google Scholar
  2. David Sherratt
    You can also search for this author inPubMed Google Scholar

Rights and permissions

About this article

Cite this article

Twigg, A., Sherratt, D. Trans-complementable copy-number mutants of plasmid ColE1.Nature 283, 216–218 (1980). https://doi.org/10.1038/283216a0

Download citation