Summary
Conjugation, the process of genetic transfer requiring cell-to-cell contact, has been the focus of many investigations. In recent years, the molecular aspect of conjugation has been questioned. Since it has been shown that during exponential growth plasmid DNA forms a complex with the folded chromosomal complex (FCC), the relationship of R64drd11 plasmid DNA to the FCC (chromosome plus membrane) during conjugal replication was examined. A cell system was used which allowed specific observation of conjugal events as they occurred in the donor cell. Evidence is presented to show that conjugally replicating R64drd11 covalently closed circular molecules co-sediment with the FCC in neutral sucrose gradients. The use of density gradients to separate DNA from membrane-bound DNA from free membrane, indicate that the membrane is the preferential structure for conjugally replicating plasmid DNA association.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Achtman M (1975) Mating aggregates in Escherichia coli conjugation. J Bacteriol 123:505–515
Achtman M, Skurray R (1977) A redefinition of the mating phenomenon in bacteria. Microbial Interactions 3:235–279
Archibold ER, Clark CW, Sheehy RJ (1978) Relationship of R6K replicating forms to the folded chromosome of Escherichia coli. J Bacteriol 135:476–482
Clark A, Warren GJ (1979) Conjugal transmission of plasmids. Annu Rev Genet 13:99–125
Clewell DB, Helinski DR (1970) Properties of a supercoiled deoxyribonucleic acid-protein relaxation complex and strand specificity of the relaxation event. Biochemistry 9:4428
Curtiss III R (1965) Chromosomal aberrations associated with mutations to bacteriophage resistance in Escherichia coli. J Bacteriol 89:28–40
Curtiss III R (1969) Bacterial Conjugation. Annu Rev Microbiol 23:69–136
Falkow S, Thompkins LS, Silvers RP, Guerry P, LeBlanc DJ (1971) The replication of R-factor DNA in Escherichia coli K-12 following conjugation. Ann NY Acad Sci 182:153–171
Fenwick RG Jr, Curtiss III R (1973) Conjugal deoxyribonucleic acid replication by Escherichia coli K-12: Effect of chloramphenicol and rifampin. J Bacteriol 116:1224–1235
Kline BC, Miller JR (1976) Detection of nonintegrated plasmid deoxyribonucleic acid in folded chromosomes of Escherichia coli: physiochemical approach to studying the unit of segregation. J Bacteriol 121:165–172
Lederberg J, Tatum EL (1946) Novel genotype in mixed cultures of biochemical mutants of bacteria. Cold Spring Harbor Symp Quant Biol 11:113–114
Nicolaidis A, Holland IB (1978) Evidence for the specific association of the chromosomal origin with outer membrane fractions isolated from Escherichia coli. J Bacteriol 135:178–189
Sheehy RJ, Novick R (1975) Studies on plasmid replication. V. Replicative intermediates. J Mol Biol 93:237–253
Sheehy RJ, Clark CW, Archibold ER (1978) Isolation of non-integrated plasmid DNA in Escherichia coli free from host folded chromosomes. Microbiology, American Society for Microbiology, p 112–113
Sueoka N, Hammers J (1974) Isolation of DNA-membrane complex in Bacillus subtilis. Proc Natl Acad Sci USA 71:4787–4791
Vapnek D, Rupp WD (1970) Asymetric segregation of the complementary sex factor DNA strands during conjugation in Escherichia coli. J Mol Biol 53:287–303
Wolf-Watz H, Horqvist A (1979) Deoxyribonucleic acid and outer membrane: Binding to outer membrane involves a specific protein. J Bacteriol 140:43–50
Author information
Authors and Affiliations
Additional information
Communicated by G.O'Donovan
Rights and permissions
About this article
Cite this article
Davis, E.J., Henry, J. Conjugal transfer replication of R64drd11 plasmid DNA in the donor cells of Escherichia coli K-12. Molec Gen Genet 187, 305–309 (1982). https://doi.org/10.1007/BF00331134
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00331134