FIG. 5.

Schematic diagram that summarizes the data on the impact of various checkpoint proteins and members of the RAD52 epistasis group on plasmid integration and excision at Ter and on HOT1 activity. The heavy arrows at RAD52 and lighter ones at RAD54 and RAD59 indicate that RAD52 was absolutely essential for both plasmid integration and HOT1 activity; the latter genes played a stimulatory role in HOT1 recombination. The question mark next to MRC1 in the plasmid integration/excision pathway indicates that the inhibitory effect was rather modest compared with that of the wild type. Previous work has shown that RAD50 was partially required for HOT1 activity. The heavy arrow next to MEC1 indicates that this gene makes a significant positive contribution to HOT1 activity.