Skip to main content
NCBI home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1969 Mar;62(3):873–880. doi: 10.1073/pnas.62.3.873

A MUTANT OF Escherichia coli PERMITTING REPLICATION OF TWO F FACTORS*

W K Maas 1,†, A D Goldschmidt 1
PMCID: PMC223679  PMID: 4895215

Abstract

Control mechanisms of replication of bacterial genetic elements are poorly understood at present. We have studied one such mechanism involving replication of the F factor in Escherichia coli. The F factor can replicate either autonomously in F+ or F′ strains, or as an integral part of the chromosome in Hfr strains. We have shown that presence of either an integrated F factor or a free F factor prevents replication of a second free F factor. Two integrated F factors can replicate in the same cell.

The present experiments show that when a F′lac element was transferred by mating into an Hfr strain, it had to become integrated into the chromosome in order to persist. With a recombination-deficient (recA) Hfr strain as recipient, the frequency of F′lac integration was greatly reduced. This permitted us to isolate a mutant Hfr strain in which the F′lac element was able to replicate autonomously. The mutation has most likely occurred in the integrated F factor itself. Availability of this new recA mutant Hfr strain facilitates genetic analysis of the F factor, since in recA+ Hfr strains frequent integration of a free F factor into the chromosome obscures recognition of complementation and recombination between two free F factors.

Full text

PDF
873

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bastarrachea F., Willetts N. S. The elimination by acridine orange of F30 from recombination-deficient strains of Escherichia coli K12. Genetics. 1968 Jun;59(2):153–166. doi: 10.1093/genetics/59.2.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. CLARK A. J. Genetic analysis of a "double male" strain of Escherichia coli K-12. Genetics. 1963 Jan;48:105–120. doi: 10.1093/genetics/48.1.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. CLARK A. J., MARGULIES A. D. ISOLATION AND CHARACTERIZATION OF RECOMBINATION-DEFICIENT MUTANTS OF ESCHERICHIA COLI K12. Proc Natl Acad Sci U S A. 1965 Feb;53:451–459. doi: 10.1073/pnas.53.2.451. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. CUZIN F. [Autonomous multiplication of the sexual episome of Escherichia coli K12 n an Hfr strain]. C R Hebd Seances Acad Sci. 1962 Jun 13;254:4211–4213. [PubMed] [Google Scholar]
  5. Clowes R. C., Moody E. E. Chromosomal transfer from "recombination-deficient" strains of Escherichia coli K-12. Genetics. 1966 Apr;53(4):717–726. doi: 10.1093/genetics/53.4.717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Cuzin F., Jacob F. Mutations de l'épisome F d'Escherichia coli K 12. I. Mutations défectives. Ann Inst Pasteur (Paris) 1967 Jan;112(1):1–9. [PubMed] [Google Scholar]
  7. Demerec M., Adelberg E. A., Clark A. J., Hartman P. E. A proposal for a uniform nomenclature in bacterial genetics. Genetics. 1966 Jul;54(1):61–76. doi: 10.1093/genetics/54.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dubnau E., Maas W. K. Inhibition of replication of an F'lac episome in Hfr cells of Escherichia coli. J Bacteriol. 1968 Feb;95(2):531–539. doi: 10.1128/jb.95.2.531-539.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Freifelder D. Studies on Escherichia coli sex factors. IV. Molecular weights of the DNA of several F' elements. J Mol Biol. 1968 Jul 14;35(1):95–102. doi: 10.1016/s0022-2836(68)80039-7. [DOI] [PubMed] [Google Scholar]
  10. Lederberg J, Cavalli L L, Lederberg E M. Sex Compatibility in Escherichia Coli. Genetics. 1952 Nov;37(6):720–730. doi: 10.1093/genetics/37.6.720. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Low B. Formation of merodiploids in matings with a class of Rec- recipient strains of Escherichia coli K12. Proc Natl Acad Sci U S A. 1968 May;60(1):160–167. doi: 10.1073/pnas.60.1.160. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. MAAS R. EXCLUSION OF A FLAC EPISOME BY AN HFR GENE. Proc Natl Acad Sci U S A. 1963 Dec;50:1051–1055. doi: 10.1073/pnas.50.6.1051. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. SCAIFE J., GROSS J. D. Inhibition of multiplication of an Flac factor in Hfr cells of Escherichia coli K-12. Biochem Biophys Res Commun. 1962 May 11;7:403–407. doi: 10.1016/0006-291x(62)90324-8. [DOI] [PubMed] [Google Scholar]
  14. Taylor A. L., Trotter C. D. Revised linkage map of Escherichia coli. Bacteriol Rev. 1967 Dec;31(4):332–353. doi: 10.1128/br.31.4.332-353.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES