Broad specificity DNA damage endonuclease

The field of the present invention is the area of DNA repair enzymes. In particular, the invention concerns the identification of stable ultraviolet DNA endonuclease polypeptide fragments, their nucleotide sequences and recombinant host cells and methods for producing them and for using them in DNA repair processes. The present disclosure describes DNA damage endonucleases which exhibit broad specificity with respect to the types of structural aberrations in double stranded DNA. These enzymes recognize double stranded DNA with distortions in structure, wherein the distortions result from photoproducts, alkylation, intercalation, abasic sites, mismatched base pairs, cisplatin adducts and inappropriately incorporated bases (for example, 8-oxoguanine, inosine, xanthine, among others). The UVDE (Uve1p) of , certain truncated forms of that UVDE (lacking from about 100 to about 250 amino acids of N-terminal sequence) and certain endonucleases from , and from . The present disclosure further provides methods for cleaving double stranded DNA having structural distortions as set forth herein using the exemplified endonucleases or their stable, functional truncated derivatives.