Function
Part of the plasmid partitioning system, which ensures the equal distribution of replicated plasmid molecules to daugther cells. The plasmids exist as well-organized plasmid foci within the nucleus that stay together throughout the cell-cycle and act as entity during segregation, effetively reducing copy number to one. Plasmid partitioning requires the proteins REP1, REP2, and a cis-acting locus STB (REP3). REP1-REP2 stably associate with CSE4-containing chromatin at STB during S-phase, marking the locus with a centromeric tag, and thereby probably catching mitotic spindle microtubules to the plasmid cluster and coupling plasmid segregation to chromosome segregation. REP1-REP2 are required to recruit the cohesin complex to the STB locus for pairing of the replicated plasmid cluster, a prerequisite for successful plasmid segregation. REP1-REP2 also negatively regulate expression of site-specific recombinase FLP and of RAF1.