Molecular and General Genetics MGG

, Volume 135, Issue 3, pp 185–190 | Cite as

Competition for DNA polymerase III between the chromosome and the R-factor R1

  • U. Marie Nordström
  • Birgitta Enberg
  • Kurt Nordström


The R-factor R1 is normally present in a low number of copies per genome in Escherichia coli K12. This number may be incrased several-fold either by lowering the growth rate or by mutation (copy mutants); these two effects act synergistically. The effect of the copy number on growth rate was tested in a strain with a temperaturesensitive DNA-polymerase III (dnaE(ts)) using wild type and copy mutants of the R-factor R1. The presence of the copy mutant R1drd-19B2 increased the temperature-sensitivity by 1.5–2°C and reduced the growth rate at temperatures close to the maximum temperature. This growth rate reduction was greater the higher the number of R1 copies/genome. The results indicate that DNA-polymerase III is involved in the replication of the plasmid R1 and that R1 and the chromosome compete for the enzyme.


Enzyme Growth Rate Escherichia Coli Rate Reduction Growth Rate Reduction 
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  1. Bertani, G.: Studies on lysogenesis. I. The mode of phage liberation by lysogenic Escherichia coli. J. Bact. 62, 296–300 (1951)Google Scholar
  2. Clowes, R. C.: Molecular structure of bacterial plasmids. Bact. Rev. 36, 361–405 (1972)PubMedGoogle Scholar
  3. Cooper, S., Helmstetter, C. E.: Chromosomal replication and the division cycle of Escherichia coli B/r. J. molec. Biol. 31, 319–340 (1968)CrossRefGoogle Scholar
  4. Engberg, B., Nordström, K.: Plasmid replication at different growth rates. Proc. Soc. gen. Microbiol. 1, 8 (1973)Google Scholar
  5. Gefter, M. L., Hirota, Y., Kornberg, T., Wechsler, J. A., Barnoux, C.: Analysis of DNA polymerase II and III in mutants of Escherichia coli thermosensitive for DNA synthesis. Proc. nat. Acad. Sci. (Wash.) 68, 3150–3153 (1971)CrossRefGoogle Scholar
  6. Goebel, W.: Replication of the colicinogenic factor E1(ColE1) at the restrictive temperature in a DNA replication mutant thermosensitive for DNA polymerase III. Nature (Lond.) New Biol. 237, 67–70 (1972)CrossRefGoogle Scholar
  7. Grinstead, J., Saunders, J. R., Ingram, I. C., Sykes, R. B., Richmond, M. H.: Properties of an R factor which originated in Pseudomonas aeruginosa 1822. J. Bact. 110, 529–537 (1972)Google Scholar
  8. Hansen, M. T., Bennett, P. M., von Meyenburg, K.: Intracistronic polarity during dissociation of translation from transcription in Escherichia coli. J. molec. Biol. 77, 589–604 (1973)CrossRefGoogle Scholar
  9. Meynell, E., Datta, N.: The relation of resistance transfer factors to the F-factor (sex-factor) of Escherichia coli K12. Genet. Res. 7, 134–140 (1966)CrossRefGoogle Scholar
  10. Meynell, E., Datta, N.: Mutant drug-resistant factors with high transmissibility. Nature (Lond.) 214, 885–887 (1967)CrossRefGoogle Scholar
  11. Nordström, K.: Increased resistance to several antibiotics by one mutation in an R-factor, R1a. J. gen. Microbiol. 66, 205–214 (1971)CrossRefGoogle Scholar
  12. Nordström, K., Engberg, B.: Plasmid replication and cell division of Escherichia coli K12. Proc. Soc. gen. Microbiol. 1, 8–9 (1973).Google Scholar
  13. Nordström, K., Ingram, L. C., Lundbäck, A.: Mutation in R factors of Escherichia coli causing an increased number of R-factor copies per chromosome. J. Bact. 110, 562–569 (1972)PubMedGoogle Scholar
  14. Nüsslein, V., Otto, B., Bonhoeffer, F., Schaller, H.: Function of DNA polymerase III in DNA replication. Nature (Lond.) New Biol. 234, 285–286 (1971)CrossRefGoogle Scholar
  15. Otto, B., Bonhoeffer, F., Schaller, H.: Purification and properties of DNA polymerase III. Europ. J. Biochem. 34, 440–447 (1973)CrossRefGoogle Scholar
  16. Slater, M., Schaechter, M.: Control of cell division in bacteria. Bact. Rev. 38, 199–221 (1974)PubMedGoogle Scholar
  17. Thompson, R., Broda, P.: DNA polymerase III and the replication of F and ColVBrp in Escherichia coli K12. Molec. gen. Genet. 127, 255–258 (1973)CrossRefGoogle Scholar
  18. Vogel, H. J., Bonner, D. M.: Acetylornithinase of Escherichia coli: partial purification and some properties. J. biol. Chem. 218, 97–106 (1956)PubMedGoogle Scholar
  19. Wechsler, J. A., Gross, J. D.: Escherichia coli mutants temperature-sensitive for DNA synthesis. Molec. gen. Genet. 113, 273–284 (1971).CrossRefGoogle Scholar
  20. Wechsler, J. A., Nüsslein, V., Otto, B., Klein, A., Bonhoeffer, F., Hermann, R., Gloger, L., Schaller, H.: Isolation and characterization of thermosensitive Escherichia coli mutants defective in deoxyribonucleic acid replication. J. Bact. 113, 1381–1388 (1973)PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1974

Authors and Affiliations

  • U. Marie Nordström
    • 1
  • Birgitta Enberg
    • 1
  • Kurt Nordström
    • 1
  1. 1.Department of MicrobiologyUniversity of UmeåUmeåSweden

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