Fig. 6. Mutations in the CTD-binding domain impair correct transcription termination. (A) Schematic diagram of plasmid pUGCYC1 showing the arrangement of M13 probes relative to the CYC1 poly(A) site (position 506). (B) Transcriptional run-on analyses performed in cells transformed with pUGCYC1 under permissive growth conditions (23°C) and after shifting to restrictive temperature (37°C) for 60 min (45 min in the case of pcf11-13 + ΔC208) as indicated. The numbers at the top of the panel correspond to the probes. Lane M marks the M13 probe used as a background hybridization control. Hybridization of transcripts to the actin probe (lane A) and RNAP III transcripts to the tRNA probe (lane t) are shown. Quantitative analyses of transcriptional run-on profiles are shown on the right of each panel. PhosphorImager quantitation was performed with IMAGEQUANT software. The M13 background was subtracted from each probe, and the results were normalized to probe 1, which was fixed at 100%. Each experiment was performed at least three times, and average values are presented.