FIG 6.

Binding of VpsT to the rpoS promoter can inhibit transcription initiation. (A) DNase I footprinting. Electropherograms show the protection pattern of a fluorescently (HEX) labeled rpoS promoter template strand digested with DNase I after incubation with bovine serum albumin (BSA) (negative control) or VpsT. The bottom panel shows the VpsT protected region (filled peaks in the BSA control) expanded from the top electropherogram. Nucleotides are numbered with reference to the first base (+1) of the rpoS start codon. (B) Sequence of the rpoS promoter region located downstream of the nlpD gene. The nlpD stop and rpoS start codons are shown in boldface type; the rpoS Shine-Dalgarno sequence (SD) is underlined, and putative −10 and −35 promoter elements are indicated by braces above the sequence. The region protected by VpsT in the template strand is boxed, and inverted repeats are indicated with arrows beneath the codon strand.