XLF acts as a flexible connector during non-homologous end joining

eLife

Metztli Cisneros-Aguirre¹  Jeremy M Stark²  Sadie C Piatt³  Sean M Carney³  Andrew T Moreno³  Felicia Wednesday Lopezcolorado⁴  Joseph J Loparo⁴ 

[1] Harvard Graduate Program in Biophysics, Harvard Medical School, Boston, United States;Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, United States;Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, United States;Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, United States;

关键词: DNA repair;    non-homologous end joining;    DNA double strand break;    single-molecule FRET;   

DOI  :  10.7554/eLife.61920

来源: DOAJ

【 摘 要 】

Non-homologous end joining (NHEJ) is the predominant pathway that repairs DNA double-strand breaks in vertebrates. During NHEJ DNA ends are held together by a multi-protein synaptic complex until they are ligated. Here, we use Xenopus laevis egg extract to investigate the role of the intrinsically disordered C-terminal tail of the XRCC4-like factor (XLF), a critical factor in end synapsis. We demonstrate that the XLF tail along with the Ku-binding motif (KBM) at the extreme C-terminus are required for end joining. Although the underlying sequence of the tail can be varied, a minimal tail length is required for NHEJ. Single-molecule FRET experiments that observe end synapsis in real-time show that this defect is due to a failure to closely align DNA ends. Our data supports a model in which a single C-terminal tail tethers XLF to Ku, while allowing XLF to form interactions with XRCC4 that enable synaptic complex formation.

【 授权许可】

Unknown