Award details

Building the segrosome a nucleoprotein machine that drives bacterial DNA segregation

Reference	BB/G003114/1
Principal Investigator / Supervisor	Dr Finbarr Hayes
Co-Investigators / Co-Supervisors
Institution	The University of Manchester
Department	Life Sciences
Funding type	Research
Value (£)	426,525
Status	Completed
Type	Research Grant
Start date	01/09/2008
End date	31/08/2011
Duration	36 months

Abstract

DNA segregation is a fundamental process that all cells, eubacterial, archaeal and eucaryotic, perform with high precision to guarantee stable transmission of genetic information at cytokinesis. The events that direct chromosome segregation in eucaryotes are much more well-defined than the molecular mechanisms that promote DNA partitioning in bacteria. The segrosome of multidrug resistance plasmid TP228 comprises ParF and ParG proteins that assemble on the parH centromere. As equivalent proteins are involved in bacterial chromosome segregation, analysis of the TP228 segrosome will also yield key insights into chromosome partitioning. Thus, the ParFG-parH complex is a tractable and informative framework in which to explore the mechanism of bacterial genome segregation. Here, we propose to dissect the events that lead to segrosome assembly in this system. Our goals include the development of in vivo and in vitro assays for centromere function, analysis of centromere topology, examination of the interaction of the ParG and ParF factors with the centromere, and structural studies of segrosome complexes. Our studies will provide new perspectives on a fundamental cellular process, DNA segregation, and will further illuminate the basis of TP228 segregation which is now among the most intensively studied plasmid partitioning systems. Moreover, in the longer term, the segregation apparatus has potential as a target for novel antibacterial agents.

Summary

Genetic information in bacterial cells principally is carried by the chromosome. However, accessory DNA elements known as plasmids can provide added genetic flexibility to the cell, for example, by permitting survival and growth in otherwise hostile environments, such as an antibiotic containing niche. Plasmids often are highly mobile between cells and can be disseminated efficiently in bacterial populations. This partly explains the rapid rise of antibiotic resistant bacteria that is now acutely problematic in clinical environments. Following bacterial chromosome and plasmid DNA replication, it is crucial that both new daughter cells acquire an intact copy of all of the genetic information at cell division. Dedicated molecular mechanisms have evolved to ensure this transmission. We are interested in understanding how precise DNA segregation occurs using genes, the proteins that they encode, and accompanying DNA sequences identified on a multidrug resistance plasmid in the model bacterium, Escherichia coli. Here we propose to employ a variety of genetic and biochemical experimental strategies with the goal of understanding how the proteins involved in segregation of this plasmid arrange into a complex on a specific plasmid DNA sequence as a first stage in the segregation process. Improving our understanding of how bacterial DNA segregation occurs ultimately could lead to the identification of new antibacterial agents that target this crucial process.

Committee	Closed Committee - Genes & Developmental Biology (GDB)
Research Topics	Microbiology, Structural Biology
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

I accept the terms and conditions of use (opens in new window)

export PDF file

back to list new search