FIG. 6.

Nucleotide sequence of the region around the promoter of ssnA and its transcription initiation site. (A) The nucleotide sequence of the region around the ssnA promoter and the N-terminal amino acid sequence of SsnA are shown. A possible ribosome-binding sequence (RBS) is underlined. The transcriptional start site of ssnA is indicated by a triangle. Restriction sites used in this study are indicated above the sequences. (B) Primer extension was performed using a fluorescein isothiocyanate-labeled primer as described in Materials and Methods. Total RNA (1 μg) from MC1000 harboring pSSNALAC in exponential phase (6-h culture) (lane 1) or in stationary phase (48-h culture) (lane 2) was used. The sequencing ladder (lanes A, C, G, and T) was obtained by using pSSNALAC DNA as a template and the same primer. An arrowhead indicates the extended band.