FIG. 2.
Effect of replacement of the natural SD of repB by the specialized SDs, SDBb and SDBc, on the expression of β-galactosidase from the repB-lacZ translational fusion in the presence (induced) and absence (uninduced) of specialized ribosomes. β-Galactosidase activities were measured by the method of Miller (25), and the values shown are averages of at least six independent determinations. A schematic representation of the lacZ fusions used is shown. The native and specialized SDs, including flanking sequences, are shown (bases shown in capital letters can pair with wt ASD, those shown in boldface type can pair with the specialized ASD, and those in plain lowercase type cannot pair with either ASD).