Fig. 3.

T7RNAP elongation is arrested by M₁dG and PdG in the transcribed strand. The ³²P-labeled transcripts from T7RNAP elongation on DNA templates with the adduct position paired with C (A) or T (B) are shown. In each panel, lanes 1, 3, and 5 contain transcripts from Xts (T) and lanes 2, 4, and 6 transcripts from Xnts (N) containing dG, M₁dG, and PdG, respectively. A 10-base DNA ladder is resolved in lane L. RO, runoff transcripts; P, pause site transcripts; X, adduct-arrested transcripts; MS, minor arrest site transcripts.