FIG. 1.

Stationary-phase induction of rpoS translation depends on the ribosome-binding sequence. The top line depicts the general fusion context. The lacUV5 promoter drives expression of a variable segment of the rpoS 5′ untranslated region (rpoS leader) followed by the first eight codons of rpoS. At this position, the lacZ gene is joined to rpoS to form a translational fusion. Five different rpoS constructs are shown, labeled according to the first nucleotide of the upstream end of the variable segment. Next to each construct is the SP induction ratio, obtained by dividing SP activity by the exponential-phase activity. The leader region of construct 1 is shown as a black line due to its length, while the broken lines indicate a magnification of the rpoS RBS. The RBS of lacZ served as a control and is labeled lacZ. Strain numbers for these constructs are as follows: 1, TE8419; 542, TE8420; 545, TE9030; 549, TE8999; 553, TE9036.