Table 2.

Identification of replication mutants displaying a mutator phenotypea

Mutant proteinAlleleTemp (°C)Relative mutation rateb% Mutation typec
DelInsNDSC
Wild-typeWild-type301.000100
Polα pol α ts11 25 185.9 85 0 15
pol α ts13 25 169.0 61 6 33
pol1-1 25 89.6 71 0 29
Polδ pol δ ts1 25 11.5 94 0 6
polδts2 25≤1.0
pol δ ts3 30 22.3 0 0 100
cdc6-121 30 12.7 0 0 100
cdc6-23 25≤1.0
Subunits of Polδ cdc1-7 25 9.1 26 0 74
cdc27-K3 30 10.1 24 0 76
Polɛ cdc20-M10 332.0
Ligase cdc17-K42 30 13.5 48 0 52
FEN-1 rad2 Δ 30 16.5 5 37 58
MCM2 cdc19-P1 30≤1.0
MCM10 cdc23-M36 25≤1.0
Orp1 cdc30 25≤1.0
  • a All mutation assays were performed at the semipermissive temperature for each strain (Table 1) or at 30°C for the nonthermosensitive strains. See Materials and Methods for description of determination of the permissive, semipermissive, and nonpermissive growth conditions. Strains that had a mutation rate at least fivefold greater than the wild-type cells were designated as having a mutator phenotype, and their values are shown in boldface type.

  • b The relative mutation rate is expressed as the fold induction relative to the wild-type mutation rate, which was 2.89 × 10−8 per generation.

  • c Del, deletion; Ins, insertion; NDSC, no detectable size change.