SAP domain forms a flexible part of DNA aperture in Ku70/80.

ABSTRACT: Nonhomologous end joining (NHEJ) is a DNA repair mechanism that religates double-strand DNA breaks to maintain genomic integrity during the entire cell cycle. The Ku70/80 complex recognizes DNA breaks and serves as an essential hub for recruitment of NHEJ components. Here, we describe intramolecular interactions of the Ku70 C-terminal domain, known as the SAP domain. Using single-particle cryo-electron microscopy, mass spectrometric analysis of intermolecular cross-linking and molecular modelling simulations, we captured variable positions of the SAP domain depending on DNA binding. The first position was localized at the DNA aperture in the Ku70/80 apo form but was not observed in the DNA-bound state. The second position, which was observed in both apo and DNA-bound states, was found belo

SUBMITTER: Hnizda A 

PROVIDER: S-EPMC8653891 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature