Fig. 6.

(A) LEE1 P1 activity measured in vivo. Both wild type and the indicated mutant E. coli (MG1655) strains were transformed with pSA508 carrying wild type (closed circles) or mutant LEE P1, LEE P1A⁺/P1B⁻ (A⁻² to G), or LEE P1A⁻/P1B⁺ (A⁻¹² to G) as described in Fig. 2. Total RNA was extracted from the bacteria at A₆₀₀=1.0 and the LEE1 P1 RNAs were analyzed by primer extension using the primer annealing to +54~+74. (B) LEE1 P1 activity measured in vivo using λ lysogens carrying wild-type or the mutant defective in either one of the promoters fused to lacZYA. Bacterial samples were taken as described in (A) for measurement of β-galactosidase activity (A₄₂₀/min/ml/A₆₀₀).