Figure 1.

Promoter regions of two of the four bubble templates used in this study. The +UP template shown contains the wild-type nontemplate strand (wtNT) in the heteroduplex region (Upper), and the −UP template contains the wild-type template strand (wtT) (Lower). Boxes highlight the −10 and −35 regions of the hag promoter. Uppercase letters represent hag DNA and lowercase letters represent vector DNA. The A-61C mutation is indicated by an asterisk. The (−UP) templates have a 9-bp deletion (indicated by Δ) to resolve RNA products in mixed transcription experiments. Note that the vector DNA extends beyond the regions shown such that the the full-length templates are 340 bp (−UP) and 370 bp (+UP).