Fig. 5.

Both terminator and associated promoter are necessary for high transcription rate at 90°C. A.

The hpyA1 terminator region was fused to the promoter region of gdh followed by 163 bp of gdh sequence. The WT and the fused DNA template were incubated 10 min at the temperatures indicated on top of the lanes. The RNA products were analysed on 6% PA gels. The transcriptional activity at 90°C, relative to the activity at 80°C which was defined as 1, is indicated below the lanes. The values for templates carrying the hpyA1 promoter were confirmed by four independent experiments.

B, Run-off transcripts from a DNA fragment carrying the gdh promoter but lacking the hypA1 terminator, and from the truncated hpyA1 template (template 3 of Fig. 4E) lacking the terminator region after restriction with BbsI. Transcription assays were performed with 46 nM RNAP, 238 nM TBP and 147 nM TFB.