The Active Partition Gene<i>incC</i>of IncP Plasmids Is Required for Stable Maintenance in a Broad Range of Hosts

Siddique, Azeem; Figurski, David H.

doi:10.1128/jb.184.6.1788-1793.2002

Cited by 26 publications

(21 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have found that, in three alpha proteobacteria, the same localization pattern occurs, making it likely that the bacteria which support replication of a broadhost-range plasmid do so because of conserved structural elements with which they interact. These results are consistent with the function of the IncC/KorB partition system of plasmid RK2 in a variety of gram-negative bacteria including A. tumefaciens (31). It is possible that there is an even wider conservation of DNA segregation machinery, as the Soj/SpoOJ partitioning system of B. subtilis is functional in E. coli (38).…”

Section: Discussionsupporting

confidence: 77%

Polar Localization of Replicon Origins in the Multipartite Genomes ofAgrobacterium tumefaciensandSinorhizobium meliloti

Kahng

Shapiro²

2003

J Bacteriol

View full text Add to dashboard Cite

The origins of replication of many different bacteria have been shown to reside at specific subcellular locations, but the mechanisms underlying their positioning and segregation are still being elucidated. In particular, little is known about the replication of multipartite genomes in bacteria. We determined the cellular positions of the origins of the replicons in the alpha proteobacteria Agrobacterium tumefaciens and Sinorhizobium meliloti and found that they are located at the poles of the cells. Our work demonstrates the conserved extreme polar localization of circular chromosome origins in these alpha proteobacteria and is also the first to specify the cellular location of origin regions from the repABC family. The cellular location of a derivative of the RK2 plasmid is distinct from that of the alpha proteobacterium genomic replicon origins but is conserved across bacteria. Colocalization experiments with the genomic replicons of A. tumefaciens revealed that the repABC replicons, although preferentially positioned at the cell pole, colocalize only rarely. For the repABC replicons in this organism, occupying discrete spatial locations may contribute to their coexistence and stable inheritance.The use of fluorescence in situ hybridization (FISH) and protein fusions to the green fluorescent protein and its variants has revealed that the bacterial cell is far more organized than previously thought and that both DNA and proteins are targeted to specific subcellular locations (30). Studies of Escherichia coli have shown that its chromosomal origin localizes to nucleoid borders near the cell poles (24), while low-copy-number plasmids localize either to the cell midpoint and near the poles (16) (R1) or to the mid-and quarter-cell positions (11, 25) (F and prophage P1). In sporulating Bacillus subtilis (35) and Caulobacter crescentus (18), chromosomal origins are found at the extreme cell poles. In synchronized populations of Caulobacter, as soon as the polar origin is replicated, it can be detected at the opposite pole of the cell (17). In vegetatively growing B. subtilis, chromosomal origins are found in subpolar positions (35). Little is known about origin positioning in bacteria with genomes of higher complexity, including several members of the alpha proteobacteria which contain multiple replicons, as well as Borrelia burgdorferi, Burkholderia cepacia, and Vibrio species, which contain two or more chromosomes (5,12,19,21,34,37). The mechanisms utilized to accurately duplicate and segregate multiple DNA molecules during the bacterial cell cycle are not known.The alpha proteobacterium Agrobacterium tumefaciens has four replicons: a circular chromosome, a linear chromosome, a cryptic plasmid (pAtC58), and the tumor-producing Ti plasmid. The circular chromosome origin of replication is similar to those of other alpha proteobacteria, whereas the other replicons carry plasmid-type replication systems of the repABC family (3, 10, 36). In previous work, we described the synchronization of DNA replication with the cel...

show abstract

Section: Discussionsupporting

confidence: 77%

Polar Localization of Replicon Origins in the Multipartite Genomes ofAgrobacterium tumefaciensandSinorhizobium meliloti

Kahng

Shapiro²

2003

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…However, true par modules are absent from the IncQ plasmids. This is not due to the broad host-range of the plasmid, since RK2 has a partitioning system that is active in a number of different hosts (Siddique and Figurski, 2002). On the other hand, the IncQ2 group of plasmids (Deane and Rawlings, 2004) (Fig.…”

Section: Conclusion: the Advantages And Disadvantages Of The Rsf10mentioning

confidence: 99%

Replication and conjugative mobilization of broad host-range IncQ plasmids

Meyer

2009

Plasmid

143

146

View full text Add to dashboard Cite

The IncQ plasmids have a broader host-range than any other known replicating element in bacteria. Studies on the replication and conjugative mobilization of these plasmids, which have mostly been focused on the nearly identical RSF1010 and R1162, are summarized with a view to understanding how this broad host-range is achieved. Several significant features of IncQ plasmids emerge from these studies: (1) initiation of replication, involving DnaA-independent activation of the origin and a dedicated primase, is strictly host-independent. (2) The plasmids can be conjugatively mobilized by a variety of different type IV transporters, including those engaged in the secretion of proteins involved in pathogenesis. (3) Stability is insured by a combination of high copy-number and modulated gene expression to reduce metabolic load.

show abstract

“…At least two essential processes contribute to the host range phenotype: replication and partition (42). However, replication has received more attention in the effort to understand the host range phenotype.…”

mentioning

confidence: 99%

Modulation of pPS10 Host Range by Plasmid-Encoded RepA Initiator Protein

et al. 2003

View full text Add to dashboard Cite

We report here the isolation and analysis of novel repA host range mutants of pPS10, a plasmid originally found in Pseudomonas savastanoi. Upon hydroxylamine treatment, five plasmid mutants were selected for their establishment in Escherichia coli at 37°C, a temperature at which the wild-type form cannot be established. The mutations were located in different functional regions of the plasmid RepA initiation protein, and the mutants differ in their stable maintenance, copy number, and ability to interact with sequences of the basic replicon. Four of them have broadened their host range, and one of them, unable to replicate in Pseudomonas, has therefore changed its host range. Moreover, the mutants also have increased their replication efficiency in strains other than E. coli such as Pseudomonas putida and Alcaligenes faecalis. None of these mutations drastically changed the structure or thermal stability of the wild-type RepA protein, but in all cases an enhanced interaction with host-encoded DnaA protein was detected by gel filtration chromatography. The effects of the mutations on the functionality of RepA protein are discussed in the framework of a threedimensional model of the protein. We propose possible explanations for the host range effect of the different repA mutants, including the enhancement of limiting interactions of RepA with specific host replication factors such as DnaA.Many plasmids are able to replicate in their original host and related species, and some of them have an extended host range which allows their establishment in several different bacterial species. At least two essential processes contribute to the host range phenotype: replication and partition (42). However, replication has received more attention in the effort to understand the host range phenotype.The study of plasmid maintenance in different hosts has been addressed by focusing on broad-host-range replicons (see references 4 and 45 for reviews), mainly RSF1010 and RK2. Plasmid RSF1010 codes for its own replication initiator proteins, allowing a host-independent initiation replication mechanism (7, 39). RK2 uses a different strategy: it synthesizes two variants of the TrfA initiation protein in the oriV region, and the initiation of replication needs the participation of one or the other of these TrfA proteins, depending on the host (11,12,41). Moreover, the number, sequence, and spacing of its several DnaA boxes also influence the replication in RK2 (8,9,40). Genetic analysis suggests that interactions between the C-terminal region of TrfA and host replication factor(s) can specifically affect plasmid host range (3). Broad-host-range plasmids replicating by rolling-circle mechanisms have also been identified, a classic example of which is pLS1 (4, 5).Narrow-host range-plasmids can also be used to identify host range determinants. A genetic approach consists in the isolation of plasmid mutants with mutations that allow their establishment in a new host. This approach has been followed with pPS10, a plasmid that can be efficie...

show abstract

The Active Partition GeneincCof IncP Plasmids Is Required for Stable Maintenance in a Broad Range of Hosts

Cited by 26 publications

References 51 publications

Polar Localization of Replicon Origins in the Multipartite Genomes ofAgrobacterium tumefaciensandSinorhizobium meliloti

Polar Localization of Replicon Origins in the Multipartite Genomes ofAgrobacterium tumefaciensandSinorhizobium meliloti

Replication and conjugative mobilization of broad host-range IncQ plasmids

Modulation of pPS10 Host Range by Plasmid-Encoded RepA Initiator Protein

Contact Info

Product

Resources

About