Plenary Talk
David Sherratt, Department of Biochemistry, University of Oxford
DNA unlinking solutions
The linkage between the two interwound strands of the DNA double
helix must be reduced to precisely zero each time DNA replicates,
if the newly replicated sister chromosomes are to be transmitted to progeny
cells prior to cell division. This requires the directed action of topisomerases
acting prior to and after replication. The complete unlinking of newly replicated chromosomes can
alternatively be compromised and facilitated by homologous and site-specific recombination processes.
I will describe how a combination of in vivo and in vitro studies is revealing the interplay and mechanisms
of the processes that lead to DNA unlinking in bacteria.
References:
Wang, X., Reyes, R. and Sherratt, D.J. (2008) Modulation of E. coli sister cohesion by topoisomerase IV. Genes. Dev. 22, 2426-2433
Reyes, R., Possoz C. and Sherratt D.J. (2008). Independent positioning and action of E. colii replication forks in living cells. Cell 133, 90-102.
Grainge I., Bregu M., Vazquez M., Sivanathan V., Ip S.C. and Sherratt D.J. (2007). Unlinking chromosome catenanes in vivo by site-specific recombination. EMBO J. 26, 4228-4238.
Ip, S., Bregu, M., Barre, F.-X., and Sherratt, D. J. (2003). Decatenation of DNA circles by FtsK-dependent Xer site-specific recombination. EMBO J, 22: 6399-6407