Figure 5.

VirB can alleviate silencing mediated by H-NS family members at the icsP promoter. Activity of the PicsP-lacZ reporter was measured in an E. coli MC4100 hns dominant-negative mutant carrying two additional inducible plasmids (pCA24N or its derivatives bearing an hns family member and pBAD or its derivative bearing virB). Each hns family member was induced (0.2 mM IPTG) from the pCA24N series throughout growth in Luria-Bertani broth at 37 °C for 5 h. In the last hour of growth, virB was induced with L-arabinose (0.2% w/v). Assays were conducted in triplicate and representative data of three independent trials are shown. A Student’s T-test was performed for statistical significance, * p < 0.05.