FIG 3.

EMSAs with purified Rex protein and the promoter regions of predicted target genes in Clostridium species other than C. acetobutylicum. (A) EMSAs were performed in the absence (lanes 1) and in the presence of 60, 300, and 1,000 nM Rex protein (lanes 2 to 4, respectively). (B) EMSAs were performed in the absence (lanes 1) and in the presence of 500, 1,000, and 1,500 nM Rex protein (lanes 2 to 4, respectively). (C) The negative controls included the ldh promoter of C. beijerinckii and the crt promoter of C. carboxidivorans, which do not contain the predicted Rex-binding site.