Experimental and Theoretical Considerations of P1-plasmid Replication and Segregation During the E. coli Cell Cycle

, Stephen Cooper; , Jay D. Keasling

Research Article

**Experimental and Theoretical Considerations of P1-plasmid Replication and Segregation During the E. coli Cell Cycle**

ABSTRACT

Two contrasting experimental descriptions of P1-plasmid replication during the cell cycle of Escherichia coli have been described. One set of results led to the proposal that replication of P1-plasmid occurs at a specific time during the cell cycle over a wide range of growth rates and follows rules similar to that governing bacterial chromosome replication. Experiments supporting this proposal utilized membrane-elution experiments, radioactive double-labeling of DNA and scintillation counting of purified plasmids. An alternative experimental description of P1-plasmid replication during the cell cycle, also based on membrane-elution methodology but measuring radioactivity incorporated into plasmid DNA by autoradiography and scanning of films, proposed that P1-plasmid replicates at all stages of the cell cycle in rapidly growing cells, but with a slight periodicity or increase in P1 replication probability within the cell cycle of slower growing cells. These discordant experimental results are analyzed. It is concluded that the direct double-label counting approach is to be preferred, as the results are consistent with a large number of experiments, are supported by theoretical considerations and yield a unified view of plasmid replication over a wide range of growth rates. Theoretical ramifications of each view of P1-plasmid replication-cycle-dependent and cycle-independent are compared. An analysis of P1-plasmid segregation is also presented.

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How to cite this article

Stephen Cooper and Jay D. Keasling, 2005. Experimental and Theoretical Considerations of P1-plasmid Replication and Segregation During the E. coli Cell Cycle. Journal of Biological Sciences, 5: 222-229.

DOI: 10.3923/jbs.2005.222.229

URL: https://scialert.net/abstract/?doi=jbs.2005.222.229

REFERENCES

Keasling, J.D., B.O. Palsson and S. Cooper, 1992. Replication of prophage P1 is cell-cycle specific. J. Bacteriol., 174: 4457-4462.
Bogan, J.A., J.E. Grimwade, M. Thornton, P. Zhou, G.D. Denning and C.E. Helmstetter, 2001. P1 and NR1 plasmid replication during the cell cycle of Escherichia coli. Plasmid, 45: 200-208.
Keasling, J.D., B.O. Palsson and S. Cooper, 1991. Cell-cycle-specific F plasmid replication: Regulation by cell size control of initiation. J. Bacteriol., 173: 2673-2680.
Helmstetter, C.E., M. Thornton, P. Zhou, J.A. Bogan, A.C. Leonard and J.E. Grimwade, 1997. Replication and segregation of a miniF plasmid during the division cycle of Escherichia coli. J. Bacteriol., 179: 1393-1399.
Cooper, S. and C.E. Helmstetter, 1968. Chromosome replication and the division cycle of Escherichia coli B/r. J. Mol. Biol., 31: 519-540.
Helmstetter, C.E. and S. Cooper, 1968. DNA synthesis during the division cycle of rapidly growing Escherichia coli B/r. J. Mol. Biol., 31: 507-518.
Hazan, R., B. Sat, M. Reches and H. Engelberg-Kulka, 2001. Postsegregational killing mediated by the P1 phage addiction module phd-doc requires the Escherichia coli programmed cell death system mazEF. J. Bacteriol., 183: 2046-2050.
Lehnherr, H., E. Maguin, S. Jafri and M.B. Yarmolinsky, 1993. Plasmid addiction genes of bacteriophage P1: Doc, which causes cell death on curing of prophage and phd, which prevents host death when prophage is retained. J. Mol. Biol., 233: 414-428.
Lehnherr, H. and M.B. Yarmolinsky, 1995. Addiction protein Phd of plasmid prophage P1 is a substrate of the ClpXP serine protease of Escherichia coli. Proc. Natl. Acad. Sci. USA., 92: 3274-3277.
Magnuson, R., H. Lehnherr, G. Mukhopadhyay and M.B. Yarmolinsky, 1996. Autoregulation of the plasmid addiction operon of bacteriophage P1. J. Biol. Chem., 271: 18705-18710.
Li, Y. and S. Austin, 2002. The P1-plasmid in action: Time-lapse photomicroscopy reveals some unexpected aspects of plasmid partition. Plasmid, 48: 174-178.
Leonard, A.C. and C.E. Helmstetter, 1986. Cell cycle-specific replication of Escherichia coli minichromosomes. Proc. Natl. Acad. Sci. USA., 83: 5101-5105.
Cooper, S., 1972. Relationship of Flac replication and chromosome replication. Proc. Natl. Acad. Sci. USA., 69: 2706-2710.
Koppes, L.J.H., 1992. Nonrandom F-plasmid replication in Escherichia coli K-12. J. Bacteriol., 174: 2121-2123.
Finkelstein, M. and C.E. Helmstetter, 1977. Cell cycle analysis of F'lac replication in Escherichia coli. B/r. J. Bacteriol., 132: 884-895.
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Cooper, S. and J.D. Keasling, 1998. Cycle-specific replication of chromosomal and F-plasmid origins. FEMS Microbiol. Lett., 163: 217-222.
Gordon, G.S., D. Sitnikov, C.D. Webb, A. Teleman and A. Straight et al., 1997. Chromosome and low copy plasmid segregation in E. coli: Visual evidence for distinct mechanisms. Cell, 90: 1113-1121.

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