FIG. 8.

PigS binds directly to the pigS-blhA intergenic region. (A) The pigS-blhA intergenic region (fragment A) and truncated fragments (fragments B to E) were generated by PCR as described in Materials and Methods. The predicted pigS and blhA −10 and −35 sequences are represented by unfilled and filled boxes, respectively. A dashed line indicates the location of the putative BigR box consensus sequence (3). (B) Binding of His₆-PigS to truncated fragments of the pigS-blhA intergenic region was assessed using EMSAs. Each lane contains a 1.5 nM concentration of the appropriate fragment of DIG-labeled DNA and either 0 or 10 nM His₆-PigS, as indicated in the figure. (C) The predicted PigS binding region shows similarity (17/20 nucleotides) to the BigR box consensus sequence, which has 100% conserved bases represented by capital letters (3). The blhA and pigS −10 sequences are underlined. An “x” indicates nucleotides that do not match the BigR consensus; a colon indicate nucleotides that match.