Fig. 9.

Activity of the pS1 promoter in vivo and its dependence on the rpoS gene function. Wild-type (WT) E. coli or ppGpp⁰ (relA spoT double mutant), rpoS and ppGpp⁰ rpoS (relA spoT rpoS triple mutant) strains were cultured in the LB medium at 37°C to exponential (exp) or stationary (st) phase of growth. Primer extension experiments were performed with primer PS1.rev as described in “Materials and methods”, and the products of the reactions were separated during polyacrylamide gel electrophoresis, with the products of the sequencing reaction (performed using the same primer) run at the same gel (lanes G, A, T and C)