Polar localization of the <i>Escherichia coli oriC</i> region is independent of the site of replication initiation

Gordon, G. Scott; Shivers, Robert P.; Wright, Andrew

doi:10.1046/j.1365-2958.2002.02901.x

Cited by 24 publications

(26 citation statements)

References 24 publications

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“…The motive force could be generated by replication itself (29), by the successive insertion of cotranslated gene products into the membrane ("transertion") (51), or by release from sibling chromosome "cohesion" (3,48). Active navigation could be provided by factors acting on a non-parS, origin-linked centromere (12,21) or by actin-like MreB proteins (9,20,25). The only direct evidence that chromosomal parAB loci act in partition is their ability to stabilize unstable vectors carrying cognate parS sites (2,10,34,52).…”

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confidence: 99%

ParABS Systems of the Four Replicons ofBurkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity

2006

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Most bacterial chromosomes carry an analogue of the parABS systems that govern plasmid partition, but their role in chromosome partition is ambiguous. parABS systems might be particularly important for orderly segregation of multipartite genomes, where their role may thus be easier to evaluate. We have characterized parABS systems in Burkholderia cenocepacia, whose genome comprises three chromosomes and one low-copynumber plasmid. A single parAB locus and a set of ParB-binding (parS) centromere sites are located near the origin of each replicon. ParA and ParB of the longest chromosome are phylogenetically similar to analogues in other multichromosome and monochromosome bacteria but are distinct from those of smaller chromosomes. The latter form subgroups that correspond to the taxa of their hosts, indicating evolution from plasmids. The parS sites on the smaller chromosomes and the plasmid are similar to the "universal" parS of the main chromosome but with a sequence specific to their replicon. In an Escherichia coli plasmid stabilization test, each parAB exhibits partition activity only with the parS of its own replicon. Hence, parABS function is based on the independent partition of individual chromosomes rather than on a single communal system or network of interacting systems. Stabilization by the smaller chromosome and plasmid systems was enhanced by mutation of parS sites and a promoter internal to their parAB operons, suggesting autoregulatory mechanisms. The small chromosome ParBs were found to silence transcription, a property relevant to autoregulation.

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ParABS Systems of the Four Replicons ofBurkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity

2006

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“…A polar location has been demonstrated for plasmid R1 in E. coli (31) and several naturally occurring plasmids of Agrobacterium tumefaciens and Sinorhizobium meliloti (20). In addition, a cell pole location has been shown for the chromosomal origins of replication of E. coli (12,32), Bacillus subtilis (26), and Caulobacter crescentus (19). In E. coli, a 25-bp sequence within the origin was identified as playing a role in the bipolar migration of a newly replicated oriC region (49).…”

Section: Discussionmentioning

confidence: 98%

Localization of the Naturally Occurring Plasmid ColE1 at the Cell Pole

2007

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The naturally occurring plasmid ColE1 was found to localize as a cluster in one or both of the cell poles of Escherichia coli. In addition to the polar localization of ColE1 in most cells, movement of the plasmid to the midcell position was observed in time-lapse studies. ColE1 could be displaced from its polar location by the p15A replicon, pBAD33, but not by plasmid RK2. The displacement of ColE1 by pBAD33 resulted in an almost random positioning of ColE1 foci in the cell and also in a loss of segregational stability, as evidenced by the large number of cells carrying pBAD33 with no visible ColE1 focus and as confirmed by ColE1 stability studies. The addition of the active partitioning systems of the F plasmid (sopABC) or RK2 (O B1 incC korB) resulted in movement of the ColE1 replicon from the cell pole to within the nucleoid region. This repositioning did not result in destabilization but did result in an increase in the number of plasmid foci, most likely due to partial declustering. These results are consistent with the importance of par regions to the localization of plasmids to specific regions of the cell and demonstrate both localization and dynamic movement for a naturally occurring plasmid that does not encode a replication initiation protein or a partitioning system that is required for plasmid stability.

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“…It appears that the origin-proximal region of the bacterial chromosome plays an analogous role to the eukaryotic centromere. However, although oriC itself is not sufficient for localization (Gordon et al 2002), regions around oriC have been reported to facilitate correct orientation, as will be discussed below (Lin & Grossman 1998;Wu & Errington 2002;Yamaichi & Niki 2004). …”

Section: Orientation Positioning and Movement Of The Bacterial Chrommentioning

confidence: 99%

Towards understanding the molecular basis of bacterial DNA segregation

Leonard

Møller‐Jensen

Löwe

2005

Phil. Trans. R. Soc. B

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Bacteria ensure the fidelity of genetic inheritance by the coordinated control of chromosome segregation and cell division. Here, we review the molecules and mechanisms that govern the correct subcellular positioning and rapid separation of newly replicated chromosomes and plasmids towards the cell poles and, significantly, the emergence of mitotic-like machineries capable of segregating plasmid DNA. We further describe surprising similarities between proteins involved in DNA partitioning (ParA/ParB) and control of cell division (MinD/MinE), suggesting a mechanism for intracellular positioning common to the two processes. Finally, we discuss the role that the bacterial cytoskeleton plays in DNA partitioning and the missing link between prokaryotes and eukaryotes that is bacterial mechano-chemical motor proteins.

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Polar localization of the Escherichia coli oriC region is independent of the site of replication initiation

Cited by 24 publications

References 24 publications

ParABS Systems of the Four Replicons ofBurkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity

ParABS Systems of the Four Replicons ofBurkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity

Localization of the Naturally Occurring Plasmid ColE1 at the Cell Pole

Towards understanding the molecular basis of bacterial DNA segregation

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