FIG. 5.
Effect of the compartmentalization of spoIIIJ expression on σG-dependent gene expression. An sspE-lacZ gene was introduced into the spoIIIJ mutant JOB44, into the wild-type strain MB24, and into the strains expressing spoIIIJ under the control of its native promoter, the spoIIQ promoter, or the spoIID promoter. The resulting strains (Table 1; see below) were grown in DSM, and samples were taken at 30-min intervals after the onset of sporulation (T0) and assayed for β-galactosidase activity. Closed squares, expression in the wild-type strain (AH1042); open circles, expression in the spoIIIJ::km mutant (JOB34); open diamonds, expression in the PspoIIIJ-spoIIIJ strain (AH5014); open triangles, expression in the PspoIIQ-spoIIIJ strain (AH5015); closed circles, expression in the PspoIID-spoIIIJ strain (AH5016). Endogeneous levels of β-galactosidase production were determined in the wild-type strain MB24 (closed triangles). Enzyme activity is expressed in Miller units (see Materials and Methods).