Fig. 3

Modification of genomic mutS to increase plasmid mutation rate. a Error-prone replication of target plasmid was influenced by synergistic action of the expression of DNA Pol I* and MutS mutant induced by temperature shift. b Reversion rate of MutS60 strain carrying pol I or pol I* gene at different temperatures for mutagenesis. For mutagenesis of the first experimental group, the cultures were grown for 10 h until at mid-exponential phase at 37 ℃, cultured to saturation for another 8 h at 43 ℃, and incubated on LB plates at 43 ℃. For the second group, the cultures were grown to saturation for 20 h at 43 ℃ and then incubated on LB plates at 30 ℃. For the third group, the temperature for both shake flask and plate growth was remained at 43 ℃. c The reversion rate of MutS60 strain containing pol I* gene at different distances from ColE1 ori