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Fate of the Replicsome Following Arrest by UV-Induced DNA Damage in Escherichia coli
Proceedings of the National Academy of Sciences of the United States of America (2013)
  • Charmain T, Courcelle, Portland State University
  • H. Arthur Jeiranian, Portland State University
  • Brandy J. Schalow, Portland State University
  • Justin Courcelle, Portland State University
Abstract

Accurate replication in the presence of DNA damage is essential to genome stability and viability in all cells. In Escherichia coli, DNA replication forks blocked by UV-induced damage undergo a partial resection and RecF-catalyzed regression before synthesis resumes. These processing events generate distinct structural intermediates on the DNA that can be visualized in vivo using 2D agarose gels. However, the fate and behavior of the stalled replisome remains a central uncharacterized question. Here, we use thermosensitive mutants to show that the replisome’s polymerases uncouple and transiently dissociate from the DNA in vivo. Inactivation of α, β, or τ subunits within the replisome is sufficient to signal and induce the RecF-mediated processing events observed following UV damage. By contrast, the helicase–primase complex (DnaB and DnaG) remains critically associated with the fork, leading to a loss of fork integrity, degradation, and aberrant intermediates when disrupted. The results reveal a dynamic replisome, capable of partial disassembly to allow access to the obstruction, while retaining subunits that maintain fork licensing and direct reassembly to the appropriate location after processing has occurred.

Disciplines
Publication Date
2013
Citation Information
Charmain T, Courcelle, H. Arthur Jeiranian, Brandy J. Schalow and Justin Courcelle. "Fate of the Replicsome Following Arrest by UV-Induced DNA Damage in Escherichia coli" Proceedings of the National Academy of Sciences of the United States of America Vol. 110 Iss. 28 (2013)
Available at: http://works.bepress.com/justin_courcelle/6/