Rowin Appanah

Abstract Break-induced replication (BIR) facilitates single-ended DNA double-strand break (DSB) repair. Upon homologous recombination-mediated strand invasion into a homologous repair template, BIR is catalysed by a minimal replisome comprising PCNA, DNA polymerase δ (Pol δ), and the Pif1 helicase. Here, we identify an interaction between Pol δ and single-stranded DNA (ssDNA)-binding protein RPA mediated by an RPA-binding module (RBM) within Pol δ subunit Pol32 and RPA subunit Rfa1.

Highlights • The N-terminal domain of Sen1 mediates replisome association • Ctf4 and Mrc1 bind to Sen1 and promote its recruitment to the replisome • The sen1-3 allele abrogates replisome binding, but not transcription termination • sen1-3 cells are sensitive to high levels of R-loops and defects of S phase checkpoint Summary DNA replication and RNA transcription compete for the same substrate during S phase. Cells have evolved several mechanisms to minimize such conflicts.