An atypical BRCT-BRCT interaction with the XRCC1 scaffold protein compacts human DNA Ligase IIIα within a flexible DNA repair complex. - Hammel M; Rashid I; Sverzhinsky A; Pourfarjam Y; Tsai MS; Ellenberger T; Pascal JM; Kim IK; Tainer JA; Tomkinson AE (Nucleic acids research, 2021)