Fig 1.

Overproduction of GreA* and DksA* alters rrnB P1::lacZ activity. The effects of overproduced GreA* and DksA* on the rrnB P1 promoter were monitored in ppGpp⁺, ppGpp⁺ dksA, ppGpp⁰, and ppGpp⁰ dksA strains by β-galactosidase assessment throughout growth. All strains were grown at 37°C in LB medium; IPTG was added to 0.1 mM when the culture reached an OD₆₀₀ of ∼ 0.1 to 0.15. Strains designated here as ppGpp⁺ correspond to a ΔrelA spoT⁺ strain. dksA−, dksA mutant.