Mycobacterial MazG Safeguards Genetic Stability via Housecleaning of 5-OH-dCTP
Figure 1
The antimutator role of MazG in Msm (A) and Mtb (B).
Both the bacterial culture conditions and the methods for determination of mutation frequencies were illustrated in Materials and Methods in detail. The frequencies conferring resistance to rifampicin in wild-type (wt), mazG-null (ΔmazG) and the complemented mutant (compl) strains were determined in exponential phase (OD600∼0.5) with or without oxidative stress and in the stationary growth phase. Oxidative stress was induced by treating exponential phase cultures with 10 mM H2O2 for 5 h (Msm) or 24 h (Mtb). Stationary phase was at the 5th-day or 28th-day of culture for Msm or Mtb, respectively. (C) Survival rate of Msm and Mtb strains after exposure to H2O2. The numbers shown are mean ± S.E. of 3 independent experiments totaling 15 cultures of Msm and 6 of Mtb.