FIG. 3.
The spoIIIGE155K allele partially bypasses the need for spoIIIJ expression for σG activity. Expression of sspE-lacZ was monitored during sporulation in the following strains (Table 1): AH5030 (spoIIIG::pEK15) (closed squares), AH5031 (spoIIIG::pEK16) (open circles), AH5024 (spoIIIG::pEK15 spoIIIJ::km) (open squares), AH5025 (spoIIIG::pEK16 spoIIIJ::km) (open diamonds), and JOB34 (spoIIIJ::km) (closed circles). Note that integration of pEK15 into the spoIIIG locus recreates a wild-type spoIIIG sequence, whereas integration of pEK16 results in expression of the spoIIIGE155K allele (see Materials and Methods). Strains were grown in DSM, and samples were taken at the indicated times after the onset of sporulation (T0) and assayed for β-galactosidase activity. The endogenous levels of β-galactosidase production were determined in the wild-type strain MB24 (closed triangles). Enzyme activity is indicated in Miller units (see Materials and Methods).