Fig. 4.

NT-box–mediated β-gal activity assay. (A) The NT-box^WT was cloned into the placZFT plasmid and transformed into a BL21 ai strain. The NT-box^mutant and NT-box^WT constructs were cloned into the placZFT plasmid and transformed into a ΔlacZ39 E. coli strain. (B) The bars represent β-gal activity ± SD, in Miller Units. (C) Primer extension analysis of the SL in the NT-box⁽ⁿ⁻²⁾ (Materials and Methods). Lane 1 corresponds to the untreated NT-box transcript. Lanes 4–7 correspond to the sequencing reactions.