Figure 6.

p4 affects bacterial growth in a bc₁-dependent manner and inhibits cytochrome bc₁ activity to reduce cytochrome c in vitro. A, the R. capsulatus WT strain was incubated with the indicated peptides for 24 h. Data indicate percent of killing. Mean ± S.D. of three independent measurements is shown. B, the indicated R. capsulatus strains were incubated with p4 for 24 h. Data indicate percent of killing for the indicated strain. Mean ± S.D. of three independent measurements for each peptide concentration is shown. ***, p < 0.001; **, p < 0.01; *, p < 0.05 by Kruskal-Wallis one-way ANOVA with post hoc Dunn's test. C, enzymatic activities of isolated cytochrome bc₁ complexes in the absence and presence of different forms of p4 at concentrations of 400 nm. Conditions were 50 mm Tris (pH 8.0), 1 mm EDTA, 0.01% n-dodecyl-d-maltoside, 20 μm decylubiquinol, and 20 μm cytochrome c. Error bars represent S.D. of the mean of four measurements.