Figure 4.
Mutations of E. coli genomic DNA by various A1 proteins. (A) The abilities of APOBEC family proteins to enhance mutagenesis levels in bacteria were analyzed. Plasmid encoding the indicated proteins was introduced into bacteria, and their expression was induced. The level of mutagenesis was then assessed by plating the bacteria on medium containing rifampicin and counting the number of RifR colonies. The median mutation frequencies of twelve independent cultures with the standard deviation are indicated as the number of RifR colonies per viable cells. (B) Western blotting of APOBEC family proteins expression in the bacterial strain analyzed in (A) was performed using an HA-tag-specific antibody.