The ATPase activity of Fml1 is essential for its roles in homologous recombination and DNA repair
Oxford University Press, 2012
Online
academicJournal
Zugriff:
In fission yeast, the DNA helicase Fml1, which is an orthologue of human FANCM, is a key component of the machinery that drives and governs homologous recombination (HR). During the repair of DNA double-strand breaks by HR, it limits the occurrence of potentially deleterious crossover recombinants, whereas at stalled replication forks, it promotes HR to aid their recovery. Here, we have mutated conserved residues in Fml1’s Walker A (K99R) and Walker B (D196N) motifs to determine whether its activities are dependent on its ability to hydrolyse ATP. Both Fml1K99R and Fml1D196N are proficient for DNA binding but totally deficient in DNA unwinding and ATP hydrolysis. In vivo both mutants exhibit a similar reduction in recombination at blocked replication forks as a fml1 Δ mutant indicating that Fml1’s motor activity, fuelled by ATP hydrolysis, is essential for its pro-recombinogenic role. Intriguingly, both fml1K99R and fml1D196N mutants exhibit greater sensitivity to genotoxins and higher levels of crossing over during DSB repair than a fml1 Δ strain. These data suggest that without its motor activity, the binding of Fml1 to its DNA substrate can impede alternative mechanisms of repair and crossover avoidance.
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The ATPase activity of Fml1 is essential for its roles in homologous recombination and DNA repair
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Autor/in / Beteiligte Person: | Nandi, Saikat ; Whitby, Matthew C. |
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Veröffentlichung: | Oxford University Press, 2012 |
Medientyp: | academicJournal |
DOI: | 10.1093/nar/gks715 |
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