Effect of 6S RNA on the transcription from σ and σ-specific promoters on linear DNA fragments

<p><b>Copyright information:</b></p><p>Taken from "Studies on the function of the riboregulator 6S RNA from : RNA polymerase binding, inhibition of transcription and synthesis of RNA-directed transcripts"</p><p></p><p>Nucleic Acids Research 2007;35(6):1885-1896.</p><p>Published online 1 Mar 2007</p><p>PMCID:PMC1874619.</p><p>© 2007 The Author(s)</p> Products from transcription reactions were separated on denaturing polyacrylamide gels and visualized by autoradiography. Reactions with the or P1 promoters are shown on the left or right side, respectively. The different holoenzymes employed (E70, E38) are indicated above the lanes. For each system the amount of 6S RNA present in the reaction was varied (lanes 1, 6, 11, 16: 0 nM, lane 2, 7, 12, 17: 10 nM, lane 3, 8, 13, 18: 50 nM, lane 4, 9, 14, 19: 100 nM, lane 5, 10, 15, 20: 250 nM). A 260 bp radiolabelled DNA fragment, indicated at the margin, was included as internal standard for quantification. The positions of the run-off transcripts for the (∼124 nt) and P1 (64 nt) promoters are marked. An arrow denotes a product that consistently arises when 6S RNA is incubated with RNA polymerase, even in the absence of any template DNA