Carreira Rodríguez, RaquelLama Díaz, TomásCrugeiras Ríos, MaríaAguado Domínguez, Francisco JavierSebesta, MarekKrejci, LumirGonzález Blanco, Miguel2024-09-272024-09-272024-07-08Nucleic Acids Research 52 12 (2024) 7012–70300305-1048http://hdl.handle.net/10347/34913Homologous recombination involves the formation of branched DNA molecules that may interfere with chromosome segregation. To resolve these persistent joint molecules, cells rely on the activation of structure-selective endonucleases (SSEs) during the late stages of the cell cycle. However, the premature activation of SSEs compromises genome integrity, due to untimely processing of replication and/or recombination intermediates. Here, we used a biochemical approach to show that the budding yeast SSEs Mus81 and Yen1 possess the ability to cleave the central recombination intermediate known as the displacement loop or D-loop. Moreover, we demonstrate that, consistently with previous genetic data, the simultaneous action of Mus81 and Yen1, followed by ligation, is sufficient to recreate the formation of a half-crossover precursor in vitro. Our results provide not only mechanistic explanation for the formation of a half-crossover, but also highlight the critical importance for precise regulation of these SSEs to prevent chromosomal rearrangementsengAtribución-NoComercial 4.0 Internacional© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/)http://creativecommons.org/licenses/by-nc/4.0/D-loop cleavageMus81Yen1DNA moleculesjournal article10.1093/nar/gkae4531362-4962open access