Smc5/6-Mms21 Prevents and Eliminates Inappropriate Recombination Intermediates in Meiosis

摘要: Repairing broken chromosomes via joint molecule (JM) intermediates is hazardous and therefore strictly controlled in most organisms. Also budding yeast meiosis, where production of enough crossovers JMs imperative, only a subset DNA breaks are repaired JMs, closely regulated by the ZMM pathway. The other to non-crossovers, avoiding JM formation, through pathways that require BLM/Sgs1 helicase. “Rogue” escape pathway eliminated before metaphase resolvases like Mus81-Mms4 prevent chromosome nondisjunction. Here, we report requirement Smc5/6-Mms21 for antagonizing rogue two mechanisms; destabilizing early resolving JMs. Elimination Mms21 SUMO E3-ligase domain leads transient accumulation, depending on resolution. Absence Smc6 persistent preventing chromatin separation. We propose complex antagonizes toxic coordinating helicases at D-Loops HJs, respectively.