Fig 7.

Light activation of the GSR without overproduction of YtvA. The β-galactosidase activity, a measure for GSR activation, was determined at various time points and is expressed in Miller units. Cultures were kept strictly in the dark until time point zero, at which time the light was switched on. Filled symbols represent cultures kept in the dark; open symbols represent illuminated cultures. (A) Comparison of strains containing RsbRA (MA7, ΔrsbRB ΔrsbRC ΔrsbRD mutants; circles) or RsbRB (MA8, ΔrsbRA ΔrsbRC ΔrsbRD mutants; triangles) as the only RsbR proteins. (B) Comparison of the single null mutant of rsbRB (PB528, triangles) and the “wild type” control strain (PB198, squares).