Involved in termination of copy-synthesis during mating-type switching. Involved in nucleotide excision repair of DNA damaged with UV light, bulky adducts, or cross-linking agents. Along with RAD16 forms an endonuclease that specifically degrades single-stranded DNA. Heterodimer composed of rad16 and swi10. Belongs to the ERCC1/RAD10/SWI10 family.