Figure 4.

Posttranscriptional, GacA-dependent regulation of a translational hcnA′-′lacZ fusion (derived from the P. fluorescens hcn operon): influence of mutations in the 5′ leader sequence. *, Nucleotides of importance are designated as follows: doubly underlined, RBS; underlined, artificial restriction sites; shaded boxes, E. coli lacZ sequence; open box, ATG initiation codon of hcnA; encircled, base substitutions; ●, deletion. ^†, β-galactosidase expression (Miller units) was determined in strains CHA0 and CHA89, when cells reached an OD₆₀₀ of 2.0–2.5. Activities are mean values from triplicate experiments ± standard deviation.