Figure 3.
Effect of Fis on mom promoter activity. (A) Effect of Fis on in vitro transcription from Pmom and Ptin7. Multiple round run-off transcription reactions were carried out using linear promoter fragments (−136 to +79) Pmom (lanes 1–4) and Ptin7 (lanes 5–8) in the presence or absence of 200 nM Fis. C (300 nM) was included as indicated. Transcription reactions were proceeded as described in ‘Materials and Methods’ section. At Ptin7, transcription is observed even in the absence of C. (B) Effect of C on Fis-mediated transcriptional repression. In vitro transcription reactions using Ptin7 template were carried out with increasing concentrations of C (as indicated) in the absence (lanes 1 and 2) or presence of Fis (100 nM in lanes 3–6 and 50 nM in lanes 7–10). (C) Densitometric analysis of the transcript bands from (B) was carried out and the values plotted.