LRET-derived HADDOCK structural models describe the conformational heterogeneity required for DNA cleavage by the Mre11-Rad50 DNA damage repair complex

eLife

Michael P Latham¹  Marella D Canny¹ 

[1] Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, United States;

关键词: P. furiosus;    Mre11-Rad50;    lanthanide resonance energy transfer;    DNA damage repair;    DNA double-strand break repair;    Other;   

DOI  :  10.7554/eLife.69579

来源: eLife Sciences Publications, Ltd

【 摘 要 】

The Mre11-Rad50-Nbs1 protein complex is one of the first responders to DNA double-strand breaks. Studies have shown that the catalytic activities of the evolutionarily conserved Mre11-Rad50 (MR) core complex depend on an ATP-dependent global conformational change that takes the macromolecule from an open, extended structure in the absence of ATP to a closed, globular structure when ATP is bound. We have previously identified an additional ‘partially open’ conformation using luminescence resonance energy transfer (LRET) experiments. Here, a combination of LRET and the molecular docking program HADDOCK was used to further investigate this partially open state and identify three conformations of MR in solution: closed, partially open, and open, which are in addition to the extended, apo conformation. Mutants disrupting specific Mre11-Rad50 interactions within each conformation were used in nuclease activity assays on a variety of DNA substrates to help put the three states into a functional perspective. LRET data collected on MR bound to DNA demonstrate that the three conformations also exist when nuclease substrates are bound. These models were further supported with small-angle X-ray scattering data, which corroborate the presence of multiple states in solution. Together, the data suggest a mechanism for the nuclease activity of the MR complex along the DNA.

【 授权许可】

CC BY