At the final step of homologous recombination, Holliday junction-containing joint molecules (JMs) are resolved to form crossover or noncrossover products. The enzymes responsible for JM resolution in vivo remain uncertain, but three distinct endonucleases capable of resolving JMs in vitro have been identified: Mus81-Mms4(EME1), Slx1-Slx4(BTBD12), and Yen1(GEN1). Using physical monitoring of recombination during budding yeast meiosis, we show that all three endonucleases are capable of promoting JM resolution in vivo. However, in mms4 slx4 yen1 triple mutants, JM resolution and crossing over occur efficiently. Paradoxically, crossing over in this background is strongly dependent on the Blooms helicase ortholog Sgs1, a component of a well-characterized anticrossover activity. Sgs1-dependent crossing over, but not JM resolution per se, also requires XPG family nuclease Exo1 and the MutLgamma complex Mlh1-Mlh3. Thus, Sgs1, Exo1, and MutLgamma together define a previously undescribed meiotic JM resolution pathway that produces the majority of crossovers in budding yeast and, by inference, in mammals.CI - Copyright (c) 2012 Elsevier Inc. All rights reserved.
|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|