FIG. 5.
Telomeric ssDNA in pol1-17 cells is removed by ExoI. CH2377 [pol1-17(short)] was grown to early log phase at 23°C and shifted to 30°C for 5 h. DNA was isolated before and after the temperature shift and incubated in the presence (lanes 2 and 4) or absence (lanes 1 and 3) of ExoI. The DNA was digested with XhoI and examined by nondenaturing in-gel hybridization (A) and denaturing hybridization (B) with a CA-oligonucleotide probe, as described in the legend to Fig. 3. Telomeric ssDNA in pol1-17 cells is lost following treatment with ExoI (compare lanes 3 and 4 in panel A). Lanes 5 and 6 contain control single-stranded and double-stranded TG1–3 DNA, respectively. Molecular weight (MW) markers (in thousands) are indicated in the middle.