Fig 3.
Effects of triple null mutations of rsbR genes on the YtvA-dependent light activation of the GSR. All strains contained a copy of lacZ, controlled by the σB-dependent ctc promoter, and pYtvA, a plasmid for overexpression of ytvA. The β-galactosidase activity was determined at various time points after IPTG induction of YtvA overexpression and expressed in Miller units. Open symbols represent cultures grown in the light; closed symbols represent cultures grown in the dark. The “wild type”-like strain PB198/pYtvA is represented by squares in all panels, while each one of the triple null mutant strains is represented by triangles. (A) The triple null mutant of rsbRB, rsbRC, and rsbRD with pYtvA (MA7/pYtvA, with RsbRA as the only RsbR protein). (B) The triple null mutant of rsbRA, rsbRC and rsbRD with pYtvA (MA8/pYtvA, with only RsbRB). Note that the lines for this mutant in the light and the dark overlay each other. (C) The triple null mutant of rsbRA, rsbRB, and rsbRD with pYtvA (MA9/pYtvA, with only RsbRC). (D) The triple null mutant of rsbRA, rsbRB, and rsbRC with pYtvA (MA10/pYtvA, with only RsbRD).