TABLE 1

Mutation frequencies (MF) and rates (μ) for wild-type and mutant RB69 DNA polymerases in vitro and in vivo

PolymeraseAPsaTotal
plaques
Mutant
plaques
Correction
factorb
MFc × 104μlacZα × 104dμrI × 10e
Pol+ Exo+-54,411520.888.4
+53,197220.953.9
±107,608740.906.2?0.043
Pol+ Exo--91,7992760.9528.6
+82,7752190.9625.5
±174,5744950.9627.13522
PolM Exo+-32,6211810.9954.9
+96,3366481.0469.6
±128,9578291.0365.910021
PolM Exo--57,9528831.08164.1263
+71,3941,5561.13246.6401
±263-40174-120
  • a Reaction conducted without (-) or with (+) accessory proteins (APs), followed by the data combined for both conditions (±) in those cases where the difference with and without APs is too small to be significant.

  • b Factor based on sequencing. Occasional light-blue mutants had no sequence change within the 293-bp lacZα sequence, while some mutants had multiple detectable mutations.

  • c Mutation frequency = (mutant plaques)(correction factor)/(total plaques).

  • d [(mutator MF) - (wild-type MF)] divided by 0.6 to adjust for the loss of mutational heteroduplexes (Bebenek and Kunkel 1995). Because there is no significant signal above the historical background of this assay for the Pol+ Exo+ gp43, no rate can be estimated.

  • e From Bebenek et al. (2001) for the T4 rI reporter sequence in vivo, which is similar in size to the lacZα reporter sequence used here (see text).