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The yeast Pif1 family helicase RRM3 promotes DNA unwinding during replisome swivelling

Presented by: 
J Baxter University of Sussex
Wednesday 5th September 2012 - 15:20 to 15:40
INI Seminar Room 1
During termination of DNA replication, replisomes overcome the topological tension that occurs as forks converge by coupling final unwinding with fork swivelling. Here I show that cells lacking the DNA helicase RRM3 accumulate terminating late replication intermediates (LRI) in plasmids both with and without characterised pause sites. Rrm3 deletion does not alter the level of swivelling that occurs during termination but its depletion extends the lifetime of LRI while it’s over-expression leads to the rapid unwinding of the LRI. Therefore RRM3 promotes DNA unwinding when the replisome swivels during termination. Potentially, this activity is also generally utilised during DNA replication to bypass topological blocks.
University of Cambridge Research Councils UK
    Clay Mathematics Institute London Mathematical Society NM Rothschild and Sons