Sae2, Exo1 and Sgs1 collaborate in DNA double-strand break processing

Eleni P. Mimitou and Lorraine S. Symington ()
Additional contact information
Eleni P. Mimitou: Columbia University Medical Center, 701 West 168th Street, New York, New York 10032, USA
Lorraine S. Symington: Columbia University Medical Center, 701 West 168th Street, New York, New York 10032, USA

Nature, 2008, vol. 455, issue 7214, 770-774

Abstract: Abstract DNA ends exposed after introduction of double-strand breaks (DSBs) undergo 5′–3′ nucleolytic degradation to generate single-stranded DNA, the substrate for binding by the Rad51 protein to initiate homologous recombination. This process is poorly understood in eukaryotes, but several factors have been implicated, including the Mre11 complex (Mre11–Rad50–Xrs2/NBS1), Sae2/CtIP/Ctp1 and Exo1. Here we demonstrate that yeast Exo1 nuclease and Sgs1 helicase function in alternative pathways for DSB processing. Novel, partially resected intermediates accumulate in a double mutant lacking Exo1 and Sgs1, which are poor substrates for homologous recombination. The early processing step that generates partly resected intermediates is dependent on Sae2. When Sae2 is absent, in addition to Exo1 and Sgs1, unprocessed DSBs accumulate and homology-dependent repair fails. These results suggest a two-step mechanism for DSB processing during homologous recombination. First, the Mre11 complex and Sae2 remove a small oligonucleotide(s) from the DNA ends to form an early intermediate. Second, Exo1 and/or Sgs1 rapidly process this intermediate to generate extensive tracts of single-stranded DNA that serve as substrate for Rad51.

Date: 2008
References: Add references at CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
https://www.nature.com/articles/nature07312 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:455:y:2008:i:7214:d:10.1038_nature07312

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature07312

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().