RMI1

Meiosis

During meiosis in budding yeast Saccharomyces cerevisiae, TOP3 (a type I topoisomerase) and its accessory factor RMI1 form a heterodimer that functions to allow passage of one DNA single strand through another. The TOP3-RMI1 heterodimer associates with Sgs1 (Bloom helicase ortholog) to form a complex that catalyzes dissolution of double Holliday junctions. Furthermore, the TOP3-RMI1 heterodimer participates in all meiotic recombination functions associated with Sgs1, most significantly as an early recombination intermediate chaperone, promoting regulated crossover and non-crossover recombination and preventing accumulation of aberrant recombination intermediates. In particular, the TOP3-RMI1–SGS1 complex promotes early formation of non-crossover recombinants during meiosis.