YEAST DNA RECOMBINATION AND REPAIR PROTEINS RAD1 AND RAD10 CONSTITUTEA COMPLEX INVIVO MEDIATED BY LOCALIZED HYDROPHOBIC DOMAINS

The Saccharomyces cerevisiae Rad1 and Rad10 proteins are required for damage-specific incision during nucleotide excision repair and also fo r certain mitotic recombination events between repeated sequences. Pre viously we have demonstrated that Rad1 and Rad10 form a specific compl ex in vitro. Using the 'two-hybrid' genetic assay system we now report that Rad1 and Rad10 proteins are subunits of a specific complex in th e cell nucleus. The Rad10-binding domain of Rad1 protein maps to a loc alized region between amino acids 809-997. The Rad1-binding domain of Rad10 protein maps between amino acids 90-210. These domains are evolu tionarily conserved and are hydrophobic in character. Although signifi cant homology exists between Rad10 and the human-DNA-repair protein Er cc1 in this region, we were unable to detect any interaction between E rcc1 and Rad1 proteins. We conclude that Rad1 and Rad10 operate in DNA repair and mitotic recombination as a constitutive complex.