Table 1.

Error rates of exonuclease-deficient (WT exo) or exonuclease-proficient (WT/CS/HY/HW exo+) Pol δ variants in the presence of PCNA in a pSJ4-lacZα forward mutation assay.

Pol δ + PCNATotal number of coloniesaNumber of white mutantsCorrected mutant frequencybError ratec
WT exo14,875855.5 × 10−31.2 × 10−4
WT exo+20,245401.8 × 10−34.1 × 10−5
CS exo+18,176723.8 × 10−38.6 × 10−5
HY exo+20,153683.2 × 10−37.2 × 10−5
HW exo+20,814974.5 × 10−31.0 × 10−4
  • a The fidelity of each polymerase variant was determined in three separate experiments. The aggregated numbers are given.

  • b Mutant frequency equals: (number of white colonies/total number of colonies) – background mutant frequency. A background mutant frequency of 5.5 × 10−6 was used for gapped pSJ4.

  • c Error rate is the number of mistakes made per base incorporated. The corrected mutant frequency was converted to error rate as previously described (Keith et al, 2013). An expression frequency (P) of 0.3 was used. Because of the limited amount of sequencing data, a set Ni/N value of 1 was used and the number of detectable sites (D) was the sum of the determined base substitutions plus insertions/deletions, that is, 145 in pSJ4.