Figure 2.

(A) Quantitative analysis of the suppression efficiency of a high dosage of EXO1. Mutant mre11 (HTY837), rad50 (HTY838), and rad52 (HTY975) strains containing YEplac195, YEpEXO1 (pHT131), or YEpMRE11 (pHT127) were cultured and plated on SD-URA plates containing various concentrations of MMS. Colonies were counted after 5 d at 30°C and normalized to the number of colonies formed in the absence of MMS. (B) MMS sensitivity of the exo1 null mutant. (C) MMS sensitivity of double mutants. (B and C) Wild-type (HTY836), exo1 (HTY1013), mre11 (HTY837), rad50 (HTY838), mre11 exo1 (HTY1015), and rad50 exo1 (HTY1017) were cultured and plated on YPD plates containing various concentrations of MMS. Survival fractions were calculated as in A. Each experiment was performed at least twice for each strain; the results of single representative experiments are shown here.