National Center for
5DAC: Atp-gamma-s Bound Rad50 From Chaetomium Thermophilum In Complex With Dna
EMBO J. (2016) 35 p.759-772
The Mre11-Rad50-Nbs1 (MRN) complex is a central factor in the repair ofDNAdouble-strand breaks (DSBs). TheATP-dependent mechanisms of howMRNdetects and endonucleolytically processesDNAends for the repair by microhomology-mediated end-joining or further resection in homologous recombination are still unclear. Here, we report the crystal structures of theATPgammaS-bound dimer of the Rad50(NBD)(nucleotide-binding domain) from the thermophilic eukaryoteChaetomium thermophilum(Ct) in complex with eitherDNAorCtMre11(RBD)(Rad50-binding domain) along with small-angle X-ray scattering and cross-linking studies. The structure andDNAbinding motifs were validated byDNAbinding experimentsin vitroand mutational analyses inSaccharomyces 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 ofDNAalong the dimer interface in anATP-dependent fashion or bridges two DNAends with a preference for 3' overhangs. Finally, our results may provide a general framework for the interaction ofABC ATPase domains of the Rad50/SMC/RecN protein family with DNA.
* Click molecule labels to explore molecular sequence information.