XPF-ERCC1 and XPG proteins are nucleases that are involved in human nucleotide excision repair. In this study, we characterized the structure-specific junction-cutting activities of both nucleases using DNA substrates containing a bubble or loop structure. We found that the junction-cutting activities of XPF-ERCC1 and XPG were greatly stimulated by human replication protein A (RPA), while heterologous single-stranded DNA-binding proteins could not substitute for human RPA. To test for specific interaction between RPA and XPF-ERCC1 as is known to occur between RPA and XPG, we employed a pull-down assay with immobilized "bubble" substrate. We found that the binding of XPF-ERCC1 complex to the bubble substrate was enhanced by RPA, suggesting a possible mechanism for RPA in the excision nuclease system, that is the targeting of the nuclease subunits to their specific sites of action. Furthermore, the RPA-promoted junction cutting by XPF-ERCC1 and XPG nucleases was observed with "loop" substrates as well, raising the possibility that XPF-ERCC1, XPG, and RPA may function in removing loop structures from DNA, independent of the other subunits of the human excinuclease.
|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||Reference||Annotation Extension|
|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||Conditions||Strain||Source||Reference|