FIG. 6.

Effects of promoter deletions on GadX and GadW regulation of gadA. Cells were grown to exponential phase in LB medium buffered to pH 8 with 100 mM MOPS or to pH 5.5 with 100 mM MES and were examined for β-galactosidase activity (Miller units). (A) gadA-lacZ fusions; (B) gadA-lacZ fusions; and (C) gadA-lacZ fusions. The length of the gadA promoter region (in nucleotides) is given along top of panels. Wild type (WT), EF833, EF932, and EF931; ΔX, EF839, EF949, and EF948; ΔXW, EF933, EF935, and EF934; and ΔW, EF921, EF923, and EF922.