FIG. 5.
Regulation of PnfrA-PxylA hybrids. The sequences of the respective promoter variants are shown. Sequences derived from PxylA are shown by a shaded background. The promoters were cloned into plasmid pDL; the resulting plasmids were integrated into the amyE gene of B. subtilis 168 to give the respective B. subtilis strains. BgaB activity was determined with cell extracts from unstressed and heat-shocked cells. The induction ratios are shown at the right. The predicted transcriptional start points of the respective RNAs are indicated by bold letters. The uninduced activities (in Miller units) of the respective promoter derivatives were as follows: DIPA4, 3 ± 0.5 U; B49, 1 ± 0.1 U; DXyl1035, 0.6 ± 0.1 U; DXyl10, 62 ± 6; DXyl35, 0.6 ± 0.2 U; DXyl10Δ2, 1 ± 0.1 U; DXyl35Δ2, 0.5 ± 0.1 U; and DXyl, 62 ± 7 U. The activity of the control, B. subtilis DL, was 0.2 ± 0.1 U (not shown).