title: Recombination and chromosome segregation.
abstract: The duplication of DNA and faithful segregation of newly replicated chromosomes at cell division is frequently dependent on recombinational processes. The rebuilding of broken or stalled replication forks is universally dependent on homologous recombination proteins. In bacteria with circular chromosomes, crossing over by homologous recombination can generate dimeric chromosomes, which cannot be segregated to daughter cells unless they are converted to monomers before cell division by the conserved Xer site-specific recombination system. Dimer resolution also requires FtsK, a division septum-located protein, which coordinates chromosome segregation with cell division, and uses the energy of ATP hydrolysis to activate the dimer resolution reaction. FtsK can also translocate DNA, facilitate synapsis of sister chromosomes and minimize entanglement and catenation of newly replicated sister chromosomes. The visualization of the replication/recombination-associated proteins, RecQ and RarA, and specific genes within living Escherichia coli cells, reveals further aspects of the processes that link replication with recombination, chromosome segregation and cell division, and provides new insight into how these may be coordinated.
authors.affiliation: Division of Molecular Genetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK. sherratt@bioch.ox.ac.uk
authors.forename: David J
authors.initials: DJ
authors.lastname: Sherratt
authors.forename: Britta
authors.initials: B
authors.lastname: Søballe
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Barre
authors.forename: Sergio
authors.initials: S
authors.lastname: Filipe
authors.forename: Ivy
authors.initials: I
authors.lastname: Lau
authors.forename: Thomas
authors.initials: T
authors.lastname: Massey
authors.forename: James
authors.initials: J
authors.lastname: Yates
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D020090:Chromosome Segregation / Q000502:physiology*; D004265:DNA Helicases / Q000378:metabolism; D004261:DNA Replication; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins / Q000378:metabolism; D053484:RecQ Helicases; D011995:Recombination, Genetic / Q000502:physiology*
chemical_list: D029968:Escherichia coli Proteins; C096452:FtsK protein, E coli; D008565:Membrane Proteins; D000251:Adenosine Triphosphatases; C506724:RecQ protein, E coli; D004265:DNA Helicases; D053484:RecQ Helicases