FIG 7 .

GcsR has divalent-cation-dependent phosphatase activity. A 5 µM sample of His₆-GcsR was incubated with the substrate p-nitrophenylphosphate in the absence of any cofactor or in the presence of 2 mM glycine, 2 mM Mg²⁺, 2 mM Zn²⁺, or 2 mM Co²⁺. Data points represent mean values ± the standard deviations (n = 3). Analysis of variance was performed by using Dunnett’s post hoc test (α value of 0.05) to identify significant differences (P < 0.0001; marked with an asterisk).