mazG-null Msm exhibited elevated CG to TA mutation under oxidative stress conditions and in the stationary phase of growth.

Spontaneous rifampicin-resistant colonies were collected from 3 independent experiments (see Methods). Cluster I region of rpoB were PCR-amplified using pfu DNA polymerase and sequenced bi-directionally. All of the sequenced colonies contain single non-synonymous mutations (see also Table S1 and S2). wt, wild-type Msm; ΔmazG, mazG-null Msm.