TONSL

Component of the MMS22L-TONSL complex, a complex that promotes homologous recombination-mediated repair of double-strand breaks (DSBs) at stalled or collapsed replication forks. The MMS22L-TONSL complex is required to maintain genome integrity during DNA replication. It mediates the assembly of RAD51 filaments on single-stranded DNA (ssDNA): the MMS22L-TONSL complex is recruited to DSBs following histone replacement by histone chaperones and eviction of the replication protein A complex (RPA/RP-A) from DSBs. Following recruitment to DSBs, the TONSL-MMS22L complex promotes recruitment of RAD51 filaments and subsequent homologous recombination. Within the complex, TONSL acts as a histone reader, which recognizes and binds newly synthesized histones following their replacement by histone chaperones. Specifically binds histone H4 lacking methylation at 'Lys-20' (H4K20me0) and histone H3.1..

Function from UniProtKB (Q96HA7), read 2026-09-23. CC BY 4.0.