Structural and functional insights into the interaction between Ku70/80 and Pol X family polymerases in NHEJ
Year: 2025
Type: article
Abstract: Non-homologous end joining (NHEJ) is the main repair pathway for double-strand DNA breaks (DSBs) in mammals. DNA polymerases lambda (Pol λ) and mu (Pol μ), members of the Pol X family, play a key role in this process. However, their interaction within the NHEJ complexes is unclear. Here, we present cryo-EM structures of Pol λ in complex with the DNA-PK long-range synaptic complex, and Pol μ bound to Ku70/80-DNA. These structures identify interaction sites between Ku70/80 and Pol X BRCT domains. Using mutants at the proteins interface in functional assays including cell transfection with an original gap-filling reporter, we define the role of the BRCT domain in the recruitment and activity of the two Pol X members in NHEJ and in their contribution to cell survival following DSBs. Finally, we propose a unified model for the interaction of all Pol X members with Ku70/80.
Source: Nature Communications
Institutions: Centre National de la Recherche Scientifique, Université Toulouse III - Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, University of Leicester, University of Cambridge, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Institut de Biologie Intégrative de la Cellule, CEA Paris-Saclay
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $6,990
Awards: Multifaceted roles of Ku in genome stability, Structural classification of NHEJ pathways; unravelling the role of Ku-binding proteins, Programmed DNA elimination in a unicellular model: coordination between DNA cleavage and double-strand break repair, G4373223218, G4399195447, Deciphering the protein choreography orchestrated by Ku threaded onto broken DNA, G4964816082, G7240651115, France-BioImaging (Biological Imaging Next-Generation Instrument), Infrastructure Française pour la Biologie Structurale Intégrée, Mechanisms of Telomere Protection
OpenAlex ID: W4410120540