Catalytic component of a structure-specific DNA repair endonuclease responsible for the 5-prime incision during DNA repair, and which is essential for nucleotide excision repair (NER) and interstrand cross-link (ICL) repair. Heterodimer composed of ERCC1 and ERCC4/XPF (PubMed:10413517, PubMed:25538220, PubMed:32034146, PubMed:16076955, PubMed:16338413). Interacts with SLX4/BTBD12; this interaction is direct and links the ERCC1-ERCC4/XPF complex to SLX4, which may coordinate the action of the structure-specific endonuclease during DNA repair (PubMed:19596235, PubMed:19596236, PubMed:25538220, PubMed:19595721, PubMed:19595722). Localizes to sites of DNA damage. Acetylation at Lys-911 by KAT5 promotes interaction with ERCC1 by disrupting a salt bridge between Glu-907 and Lys-911, thereby exposing a second binding site for ERCC1 (PubMed:32034146). Deacetylated by SIRT1 (PubMed:32034146). The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the XPF family. Truncated N-terminus.