DNA double-strand breaks can result from closely-opposed breaks induced directly in complementary strands. Alternatively, double-strand breaks could be generated during repair of clustered damage, where the repair of closely-opposed lesions has to be well-coordinated. Using single and multiple mutants of budding yeast that impede interaction of DNA polymerase delta and 5'-flap endonuclease Rad27/Fen1 with the PCNA sliding clamp, we show that the lack of coordination between these components during long-patch base excision repair of alkylation damage can result in many double-strand breaks within the chromosomes of non-dividing haploid cells. This contrasts with the efficient repair of non-clustered MMS-induced lesions, as measured by quantitative PCR and S1 nuclease cleavage of single-strand break sites. We conclude that closely-opposed single-strand lesions are a unique threat to the genome and that repair of closely-opposed strand damage requires greater spatial and temporal coordination between the participating proteins than widely-spaced damage in order to prevent the development of double-strand breaks.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|