FIG. 3.
AsiA, MotA, and MotANTD each interact with the C-terminal region of σ70 in the E. coli two-hybrid assay. β-Galactosidase (β-gal) activity is plotted versus IPTG concentration for KS1 cells containing pBRα-σ70 and pcI-AsiA (•), pcI-MotANTD (▪), pcI-MotAfl (▴), pcI-Mot21NTD (□), pcI-MotA− (▵), or pACλcI32 (○). Cultures were grown continuously in the presence of the indicated concentrations of IPTG. Points and standard deviations (indicated by error bars) represent the averages of the results of three assays. In this assay, in which cultures were grown continuously in the presence of IPTG, MotANTD gave higher levels of β-galactosidase activity than did MotAfl. However, in assays in which cultures were grown for only 1 h with IPTG, the activities seen with MotANTD and MotAfl were similar (data not shown).