SPECIFIC CLEAVAGE OF MODEL RECOMBINATION AND REPAIR INTERMEDIATES BY THE YEAST RAD1-RAD10 DNA ENDONUCLEASE

The RAD1 and RAD10 genes of Saccharomyces cerevisiae are required for both nucleotide excision repair and certain mitotic recombination even ts. Here, model recombination and repair intermediates were used to sh ow that Rad1-Rad10-mediated cleavage occurs at duplex-single-strand ju nctions. Moreover, cleavage occurs only on the strand containing the 3 ' single-stranded tail. Thus, both biochemical and genetic evidence in dicate a role for the Rad1-Rad10 complex in the cleavage of specific r ecombination intermediates. Furthermore, these data suggest that Rad1- Rad10 endonuclease incises DNA 5' to damaged bases during nucleotide e xcision repair.