FIG. 1.

The spa promoter region. The filled circles of the rightward-pointing arrows indicate the start point of the subcloned promoter fragments (all clones end at +7). The fragments are identified by the 5′ end location of the fragments, which are listed to the right of the arrows. The spa start codon and the stop codon of the upstream sarS determinant are double underlined, the SarA binding sequence of Chien et al. (10) is in bold, and the range of fragments identified by Patel et al. (33) by an S1 protection assay is indicated by the underlining. The double wavy underlined sequence represents a SarA consensus binding site identified by SELEX (41). The upward-facing arrows indicate the start sites of transcription indicated by primer extension.