FIG. 4.

Effect of the sscB mutation on sseF transcription. Transcription of sseF-lacZ (A) and ssaV-lacZ (B [control]) were measured in the wild type or in the sscB mutant strain containing a chromosomal fusion of lacZ with sseF (ZP31 and ZP33, respectively) or ssaV (ZP39 and ZP40, respectively). Stationary-phase bacteria grown in LB medium were washed twice, diluted in MgM5 or MgM7, and grown for an additional 6 h. Samples were then collected and assayed for β-galactosidase activities (Miller units). The experiments were carried out three times with similar results.