regulatory subunit of different structure-specific endonucleases. Required for DNA recombination and repair. Together with SLX1 forms a Holliday junction (HJ) resolvase. Has several distinct roles in protecting genome stability by resolving diverse forms of deleterious DNA structures originating from replication and recombination intermediates and from DNA damage. Component of the SLX1-SLX4 structure-specific endonuclease that resolves DNA secondary structures generated during DNA repair and recombination. Has endonuclease activity towards branched DNA substrates, introducing single-strand cuts in duplex DNA close to junctions with ss-DNA. Has a preference for 5'-flap structures, and promotes symmetrical cleavage of static and migrating HJs. Resolves HJs by generating two pairs of ligatable, nicked duplex products. Interacts with the structure-specific ERCC4-ERCC1 endonuclease and promotes the cleavage of bubble structures. Interacts with the structure-specific MUS81-EME1 endonuclease and promotes the cleavage of 3'-flap and replication fork-like structures. Required for recovery from alkylation-induced DNA damage and is involved in the resolution of DNA double-strand breaks. Involved in Rad1/Rad10pdependent removal of 3'-nonhomologous tails during DSBR via single-strand annealing. Interacts with MSH2; component of the MSH2-MSH3 mismatch repair complex. Interacts with TERF2-TERF2IP. Interacts with PLK1 and C20ORF94. Localizes to sites of DNA damage. Two alternatively spliced human isoforms have been described. Note: This description may include information from UniProtKB.
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.