Download MendeleyStructural mechanism of ATP-dependent DNA binding and DNA end bridging by eukaryotic Rad50.
Seifert, F.U., Lammens, K., Stoehr, G., Kessler, B., Hopfner, K.P.(2016) EMBO J 35: 759-772
- PubMed: 26896444
- DOI: https://doi.org/10.15252/embj.201592934
- Primary Citation of Related Structures:
5DA9, 5DAC - PubMed Abstract:
The Mre11-Rad50-Nbs1 (MRN) complex is a central factor in the repair of DNA double-strand breaks (DSBs). The ATP-dependent mechanisms of how MRN detects and endonucleolytically processes DNA ends for the repair by microhomology-mediated end-joining or further resection in homologous recombination are still unclear. Here, we report the crystal structures of the ATPγS-bound dimer of the Rad50(NBD)(nucleotide-binding domain) from the thermophilic eukaryote Chaetomium thermophilum(Ct) in complex with either DNA or CtMre11(RBD)(Rad50-binding domain) along with small-angle X-ray scattering and cross-linking studies. The structure and DNA binding motifs were validated by DNA binding experiments in vitro and mutational analyses in Saccharomyces cerevisiae in vivo Our analyses provide a structural framework for the architecture of the eukaryotic Mre11-Rad50 complex. They show that a Rad50 dimer binds approximately 18 base pairs of DNA along the dimer interface in anATP-dependent fashion or bridges two DNA ends with a preference for 3' overhangs. Finally, our results may provide a general framework for the interaction of ABC ATPase domains of the Rad50/SMC/RecN protein family with DNA.
Organizational Affiliation:
Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany.
