Processing of DNA double-stranded breaks and intermediates of recombination and repair by Saccharomyces cerevisiae mre11 and its stimulation by Rad50, Xrs2, and Sae2 proteins

Abstract

Background: The mechanism of DSB end resection in yeast nuclease deficient mre11 mutants and Mre11 nucleaseindependent ATM activation in mammalian cells remains unclear. Results: Mre11 binds to DSB ends and also promotes end bridging. Rad50, Xrs2, and Sae2 potentiate Mre11-catalyzed DNA unwinding activity. Conclusion: Mre11 nuclease activity is dispensable for DNA binding and unwinding activity. Significance: These studies reveal a novel mechanism of processing of DSBs by MRX-Sae2 complex. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.