title: Single molecule approaches to monitor the recognition and resection of double-stranded DNA breaks during homologous recombination.
abstract: The fate of a cell depends on its ability to repair the many double-stranded DNA breaks (DSBs) that occur during normal metabolism. Improper DSB repair may result in genomic instability, cancer, or other genetic diseases. The repair of a DSB can be initiated by the recognition and resection of a duplex DNA end to form a 3'-terminated single-stranded DNA overhang. This task is carried out by different single-strand exonucleases, endonucleases, and helicases that work in a coordinated manner. This manuscript reviews the different single-molecule approaches that have been employed to characterize the structural features of these molecular machines, as well as the intermediates and products formed during the process of DSB repair. Imaging techniques have unveiled the structural organization of complexes involved in the tethering and recognition of DSBs. In addition to that static picture, single molecule studies on the dynamics of helicase-nuclease complexes responsible for the processive resection of DSBs have provided detailed mechanistic insights into their function.
authors.affiliation: Centro Nacional de Biotecnología, CSIC, Campus UAM, Darwin 3, Cantoblanco, 28049 Madrid, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Carrasco
authors.affiliation: School of Biochemistry, Medical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, UK.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dillingham
authors.affiliation: Centro Nacional de Biotecnología, CSIC, Campus UAM, Darwin 3, Cantoblanco, 28049 Madrid, Spain. Electronic address: fernando.moreno@cnb.csic.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Moreno-Herrero
mesh_terms: D000818:Animals; D053903:DNA Breaks, Double-Stranded; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods; D059767:Recombinational DNA Repair
keywords: AddAB; DNA end resection; DNA helicase; Double-stranded DNA break repair; RecBCD; Single molecule