Plasmids and Conjugation Systems Other Than F
Not all plasmids are conjugative, and even those that are do not necessarily have chromosome-mobilizing ability (i.e., the ability to promote transfer of chromosomal markers to a recipient cell). Nevertheless, these plasmids can have major economic and genetic importance. The diversity of plasmids that have been identified is staggering, and they are ubiquitous. In one study, 34 of 87 hospital isolates of enteric bacteria or Pseudomonas carried at least one plasmid. Bacillus megaterium routinely has eight or more plasmids in its cytoplasm. All of these plasmids have only two things in common. They can be identified in cell lysates as autonomous DNA molecules, and they are capable of self-replication. If the presence or absence of a plasmid has no observable effect on the cell phenotype, it is a cryptic plasmid. Researchers often subdivide plasmids according to their capacity for self-transfer from one host cell to another using the F plasmid as the standard for comparison.
KeywordsTetracycline Resistance Conjugation System Conjugative Plasmid Incompatibility Group Resistance Plasmid
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- Clewell, D.B. (ed.) (1993). Bacterial Conjugation. New York: Plenum Press. (Included are chapters on Ti plasmids, R100, conjugative transposition, and pheromone effects.)Google Scholar
- Luria, S.E., Suit, J.L (1987). Colicins and Col plasmids, pp. 1615–1624. In: Neidhardt, F.C. et al. (eds.), Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology. Washington, DC: American Society for Microbiology.Google Scholar
- Meijer, W.J.J., Wisman, G.B.A., Terpstra, P, Thorsted, PB., Thomas, C.M., Holsappel, S., Venema, G., Bron, S. (1998). Rolling-circle plasmids from Bacillus subtilis: Complete nucleotide sequences and analyses of genes of pTA1015, pTA1040, pTA1050 and pTA1060, and comparisons with related plasmids from gram-positive bacteria. FEMS Microbiology Reviews 21: 337–368.PubMedCrossRefGoogle Scholar
- O’Brien, S.J. (1993). Genetic Maps, 6th ed. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.Google Scholar
- Lee, S.H., Frost, L.S., Paranchych, W. (1992). FinOP repression of the F plasmid involves extension of the half-life of FinP antisense RNA by FinO. Molecular and General Genetics 235: 131–13 9.Google Scholar
- Nakayama, J., Takanami, Y., Horii, T., Sakuda, S., Suzuki, A. (1998). Molecular mechanism of peptide-specific pheromone signaling in Enterococcus faecalis: Functions of pheromone receptor TraA and pheromone-binding protein TraC encoded by plasmid pPD1. Journal of Bacteriology 180: 449–456.PubMedGoogle Scholar