FIG. 4.

Impact of deletions of genes encoding checkpoint proteins and recombination proteins on HOT1 activity. (A) Schematic diagram showing the HOT1 assay; the E elements (containing the Fob1 binding site) and the I elements are shown; recombination between the flanking his4 genes excises URA3, which has no ARS and therefore is eliminated from the cells. (B) HOT1 activity in the absence of checkpoint adapter proteins. (C) HOT1 activity in the absence of MEC1 and RAD53. (D) HOT1 activity in different strains with individual deletions of the various members of the RAD52 epistasis group. WT, wild type.