Fig 8.
Y. pestis PyscN reporter activity is sensitive to substitutions that disrupt the ExsA binding site. (A) The PyscN promoter sequence showing the ExsA consensus sequence in binding site 1. The GnC and TGnnA sequences are highlighted in bold, and each promoter nucleotide substitution is indicated with an arrow. (B) The PA103 exsA::Ω strain carrying the indicated mutant PyscN-lacZ transcriptional reporters was transformed with either pExsA or pLcrF. The resulting strains were cultured in the presence of EGTA and assayed for β-galactosidase activity. Activation by pExsA (open bars) and pLcrF (hatched bars) is reported as the percent activity of the mutant promoters normalized to the activity at the wild-type PyscN promoter.