scholarly journals Active Stable Maintenance Functions in Low Copy-Number Plasmids of Gram-positive Bacteria. I. Partition Systems

2013 ◽  
Vol 62 (1) ◽  
pp. 3-16 ◽  
Author(s):  
MICHAŁ DMOWSKI ◽  
GRAŻYNA JAGURA-BURDZY
Keyword(s):  
Cell Division ◽  
Copy Number ◽  
Significant Contribution ◽  
Bacterial Cell Division ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Daughter Cells ◽  
Low Copy Number ◽  
Random Segregation ◽  
Stable Maintenance

Low copy number plasmids cannot rely on the random segregation during bacterial cell division. To be stably maintained in the population they evolved two types of mechanisms (i) partition systems (PAR) that actively separate replicated plasmid molecules to the daughter cells and (ii) toxin-andidote systems (TA) that act after cell division to kill plasmid-less cells. Our knowledge of partition systems has been based mainly on analysis of plasmids from Gram-negative bacteria. Now, numerous partition systems of plasmids from Gram-positive bacteria have also been characterized and make significant contribution to our understanding of these mechanisms.

scholarly journals Active Stable Maintenance Functions in Low Copy-Number Plasmids of Gram-positive Bacteria. II. Post-Segregational Killing Systems

2013 ◽  
Vol 62 (1) ◽  
pp. 17-22 ◽  
Author(s):  
MICHAŁ DMOWSKI ◽  
GRAŻYNA JAGURA-BURDZY
Keyword(s):  
Cell Growth ◽  
Copy Number ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Daughter Cells ◽  
Low Copy Number ◽  
Stable Maintenance

Active support is needed for low copy-number plasmids to be stably maintained in bacterial cells. The mechanisms that fulfill this role are (i) partition systems (PAR) acting to separate plasmid molecules to daughter cells and (ii) toxin-andidote (TA) (post-segregational killing-PSK) systems which arrest cell growth until the plasmid reaches the correct copy-number or kill the cells that have not inherited the plasmid. Our knowledge of toxin-antidote systems comes mainly from studies on Gram-negative bacteria. However, some addiction systems of Gram-positive bacteria have been characterized in detail or recently identified. Altogether, they bring new interesting data on toxin-antidote functioning in bacteria.

Plasmid vectors for Gram-positive bacteria switching from high to low copy number

Gene ◽  
1996 ◽  
Vol 183 (1-2) ◽  
pp. 175-182 ◽  
Author(s):  
Pierre Renault ◽  
Gerard Corthier ◽  
Nathalie Goupil ◽  
Christine Delorme ◽  
S.Dusko Ehrlich
Keyword(s):  
Copy Number ◽  
Gram Positive ◽  
Plasmid Vectors ◽  
Gram Positive Bacteria ◽  
Low Copy Number

scholarly journals ¡vIVA la DivIVA!

2019 ◽  
Vol 201 (21) ◽  
Author(s):  
Lauren R. Hammond ◽  
Maria L. White ◽  
Prahathees J. Eswara
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Parental Cell ◽  
Model Organisms ◽  
Posttranslational Regulation ◽  
Bacterial Cell Division ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Division Cell

ABSTRACT Reproduction in the bacterial kingdom predominantly occurs through binary fission—a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped Escherichia coli and Bacillus subtilis, which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.

scholarly journals The Toxin-Antitoxin System of the Streptococcal Plasmid pSM19035

2005 ◽  
Vol 187 (17) ◽  
pp. 6094-6105 ◽  
Author(s):  
Urszula Zielenkiewicz ◽  
Piotr Cegłowski
Keyword(s):  
Streptococcus Pyogenes ◽  
Copy Number ◽  
Bacterial Species ◽  
Erythromycin Resistance ◽  
Gram Positive ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Copy Number Plasmid ◽  
Low Copy Number ◽  
Function Expression

ABSTRACT pSM19035 of the pathogenic bacterium Streptococcus pyogenes is a low-copy-number plasmid carrying erythromycin resistance, stably maintained in a broad range of gram-positive bacteria. We show here that the ω-ε-ζ operon of this plasmid constitutes a novel proteic plasmid addiction system in which the ε and ζ genes encode an antitoxin and toxin, respectively, while ω plays an autoregulatory function. Expression of toxin Zeta is bactericidal for the gram-positive Bacillus subtilis and bacteriostatic for the gram-negative Escherichia coli. The toxic effects of ζ gene expression in both bacterial species are counteracted by proper expression of ε. The ε-ζ toxin-antitoxin cassette stabilizes plasmids in E. coli less efficiently than in B. subtilis.

scholarly journals Prevalence and Significance of Plasmid Maintenance Functions in the Virulence Plasmids of Pathogenic Bacteria

2011 ◽  
Vol 79 (7) ◽  
pp. 2502-2509 ◽  
Author(s):  
Manjistha Sengupta ◽  
Stuart Austin
Keyword(s):  
Copy Number ◽  
Drug Targets ◽  
Pathogenic Bacteria ◽  
Plasmid Copy ◽  
Plasmid Partition ◽  
Plasmid Segregation ◽  
Daughter Cells ◽  
Virulence Plasmids ◽  
Low Copy Number ◽  
Stable Maintenance

ABSTRACTVirulence functions of pathogenic bacteria are often encoded on large extrachromosomal plasmids. These plasmids are maintained at low copy number to reduce the metabolic burden on their host. Low-copy-number plasmids risk loss during cell division. This is countered by plasmid-encoded systems that ensure that each cell receives at least one plasmid copy. Plasmid replication and recombination can produce plasmid multimers that hinder plasmid segregation. These are removed by multimer resolution systems. Equitable distribution of the resulting monomers to daughter cells is ensured by plasmid partition systems that actively segregate plasmid copies to daughter cells in a process akin to mitosis in higher organisms. Any plasmid-free cells that still arise due to occasional failures of replication, multimer resolution, or partition are eliminated by plasmid-encoded postsegregational killing systems. Here we argue that all of these three systems are essential for the stable maintenance of large low-copy-number plasmids. Thus, they should be found on all large virulence plasmids. Where available, well-annotated sequences of virulence plasmids confirm this. Indeed, virulence plasmids often appear to contain more than one example conforming to each of the three system classes. Since these systems are essential for virulence, they can be regarded as ubiquitous virulence factors. As such, they should be informative in the search for new antibacterial agents and drug targets.

scholarly journals Benzamide Derivatives Targeting the Cell Division Protein FtsZ: Modifications of the Linker and the Benzodioxane Scaffold and Their Effects on Antimicrobial Activity

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 160 ◽  
Author(s):  
Valentina Straniero ◽  
Lorenzo Suigo ◽  
Andrea Casiraghi ◽  
Victor Sebastián-Pérez ◽  
Martina Hrast ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Cell Division ◽  
Single Molecule ◽  
Efflux Pump ◽  
Computational Study ◽  
Structural Features ◽  
Temperature Sensitive ◽  
Bacterial Cell Division ◽  
Gram Positive ◽  
Prokaryotic Protein

Filamentous temperature-sensitive Z (FtsZ) is a prokaryotic protein with an essential role in the bacterial cell division process. It is widely conserved and expressed in both Gram-positive and Gram-negative strains. In the last decade, several research groups have pointed out molecules able to target FtsZ in Staphylococcus aureus, Bacillus subtilis and other Gram-positive strains, with sub-micromolar Minimum Inhibitory Concentrations (MICs). Conversely, no promising derivatives active on Gram-negatives have been found up to now. Here, we report our results on a class of benzamide compounds, which showed comparable inhibitory activities on both S. aureus and Escherichia coli FtsZ, even though they proved to be substrates of E. coli efflux pump AcrAB, thus affecting the antimicrobial activity. These surprising results confirmed how a single molecule can target both species while maintaining potent antimicrobial activity. A further computational study helped us decipher the structural features necessary for broad spectrum activity and assess the drug-like profile and the on-target activity of this family of compounds.

scholarly journals Distribution of Centromere-Like parS Sites in Bacteria: Insights from Comparative Genomics

2007 ◽  
Vol 189 (23) ◽  
pp. 8693-8703 ◽  
Author(s):  
Jonathan Livny ◽  
Yoshiharu Yamaichi ◽  
Matthew K. Waldor
Keyword(s):  
Comparative Genomics ◽  
Chromosome Segregation ◽  
Copy Number ◽  
Consensus Sequence ◽  
Daughter Cells ◽  
Low Copy Number ◽  
Prokaryotic Genomes ◽  
Bacterial Chromosomes ◽  
Origin Region ◽  
Bioinformatic Approaches

ABSTRACT Partitioning of low-copy-number plasmids to daughter cells often depends on ParA and ParB proteins acting on centromere-like parS sites. Similar chromosome-encoded par loci likely also contribute to chromosome segregation. Here, we used bioinformatic approaches to search for chromosomal parS sites in 400 prokaryotic genomes. Although the consensus sequence matrix used to search for parS sites was derived from two gram-positive species, putative parS sites were identified on the chromosomes of 69% of strains from all branches of bacteria. Strains that were not found to contain parS sites clustered among relatively few branches of the prokaryotic evolutionary tree. In the vast majority of cases, parS sites were identified in origin-proximal regions of chromosomes. The widespread conservation of parS sites across diverse bacteria suggests that par loci evolved very early in the evolution of bacterial chromosomes and that the absence of parS, parA, and/or parB in certain strains likely reflects the loss of one of more of these loci much later in evolution. Moreover, the highly conserved origin-proximal position of parS suggests par loci are primarily devoted to regulating processes that involve the origin region of bacterial chromosomes. In species containing multiple chromosomes, the parS sites found on secondary chromosomes diverge significantly from those found on their primary chromosomes, suggesting that chromosome segregation of multipartite genomes requires distinct replicon-specific par loci. Furthermore, parS sites on secondary chromosomes are not well conserved among different species, suggesting that the evolutionary histories of secondary chromosomes are more diverse than those of primary chromosomes.

scholarly journals Roles of the 2 microns gene products in stable maintenance of the 2 microns plasmid of Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (10) ◽  
pp. 3566-3573 ◽  
Author(s):  
A E Reynolds ◽  
A W Murray ◽  
J W Szostak
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Copy Number ◽  
Gene Products ◽  
Site Specific ◽  
Cell Cycles ◽  
Daughter Cells ◽  
Repeat Sequences ◽  
Copy Numbers ◽  
Mother And Daughter ◽  
Stable Maintenance

We have examined the replication and segregation of the Saccharomyces cerevisiae 2 microns circle. The amplification of the plasmid at low copy numbers requires site-specific recombination between the 2 microns inverted repeat sequences catalyzed by the plasmid-encoded FLP gene. No other 2 microns gene products are required. The overexpression of FLP in a strain carrying endogenous 2 microns leads to uncontrolled plasmid replication, longer cell cycles, and cell death. Two different assays show that the level of Flp activity decreases with increasing 2 microns copy number. This regulation requires the products of the REP1 and REP2 genes. These gene products also act together to ensure that 2 microns molecules are randomly segregated between mother and daughter cells at cell division.

scholarly journals Bacterial chromosome segregation.

2005 ◽  
Vol 52 (1) ◽  
pp. 1-34 ◽  
Author(s):  
Aneta A Bartosik ◽  
Grazyna Jagura-Burdzy
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Chromosome Segregation ◽  
Copy Number ◽  
Bacterial Cells ◽  
Replication Machinery ◽  
Rapid Separation ◽  
Dna Segregation ◽  
Low Copy Number ◽  
Bacterial Chromosomes

In most bacteria two vital processes of the cell cycle: DNA replication and chromosome segregation overlap temporally. The action of replication machinery in a fixed location in the cell leads to the duplication of oriC regions, their rapid separation to the opposite halves of the cell and the duplicated chromosomes gradually moving to the same locations prior to cell division. Numerous proteins are implicated in co-replicational DNA segregation and they will be characterized in this review. The proteins SeqA, SMC/MukB, MinCDE, MreB/Mbl, RacA, FtsK/SpoIIIE playing different roles in bacterial cells are also involved in chromosome segregation. The chromosomally encoded ParAB homologs of active partitioning proteins of low-copy number plasmids are also players, not always indispensable, in the segregation of bacterial chromosomes.

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