Figure 1.

Restriction digestion and post-labeling method for determining the bypass efficiencies and mutation frequencies of O²-alkyldT lesions in E. coli cells. ‘X’ in the 22-mer DNA strand designates dT or O²-alkyldT. The cleavage sites for BbsI and MluCI restriction endonucleases are indicated with broken arrows. Only partial sequence of PCR products for the lesion-containing genome is displayed, and the PCR products of the competitor genome are not shown. For LC-MS/MS analysis, the PCR products were digested with BbsI and MluCI prior to digestion using shrimp alkaline phosphatase (SAP), and the [³²P]-labeling step involving the use of T4 polynucleotide kinase (T4 PNK) was omitted.