Persistence mechanisms of conjugative plasmids.
Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting the successful propagation and long-term continued existence of these extra-chromosomal elements is extensive. Apart from the accessory genetic elements that may provide plasmid-harboring cells a selective advantage, special focus is placed on the mechanisms conjugative plasmids employ to ensure their stable maintenance in the host cell. These importantly include the ability to self-mobilize in a process termed conjugative transfer, which may occur across species barriers. Other plasmid stabilizing mechanisms include the multimer resolution system, active partitioning, and post-segregational-killing of plasmid-free cells. Finally, various molecular adaptations of plasmids to better match the genetic background of their bacterial host cell will be described.
Bahl
Martin Iain
MI
Department of Microbiology, University of Copenhagen, Copenhagen, Denmark.
Hansen
Lars Hestbjerg
LH
Sørensen
Søren J
SJ
D016375:Antisense Elements (Genetics); D001419:Bacteria / Q000235:genetics; D001482:Base Composition; D003227:Conjugation, Genetic; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial; D042822:Genomic Instability; D008957:Models, Genetic; D010957:Plasmids / Q000235:genetics*
D016375:Antisense Elements (Genetics); D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial