Runoff in vitro transcription of lipA promoter fragments. The numbers on the left indicate the positions of a 25-bp ladder of DNA fragments (Invitrogen). The integrity of the RNA polymerase preparation was confirmed by carrying out two control reactions with fragments containing the veg and ctc promoters (lanes c and v, respectively), which have been described previously (34). Lane 1, in vitro transcription of the 249-bp XbaI-BamHI fragment from pB94 in the absence of LipR protein; lane 2, transcription of the same fragment with 1 μM LipR added; lane 3, transcription of the 187-bp XbaI-BamHI fragment from pBZ619 with 1 μM LipR added; lane 4, transcription of the 139-bp XbaI-BamHI fragment from pBZ623 with 1 μM LipR added. The expected size of runoff lipA transcripts was 104 nucleotides. The arrowhead labeled ETE indicates the position of bands corresponding to end-to-end transcription of the linear fragment, and the asterisk indicates the position of a transcript which originated in the strand opposite the lipA promoter.