FIG 5.

rafX gene is required for bacterial growth, autolysis, and cell shape and division in S. pneumoniae. (A) Representative bacterial growth rate experiment. Bacteria were grown in a chemically defined medium. OD₆₀₀ was measured at the times indicated. WL represents the D39 ΔrafX mutant complemented with the full-length RafX protein. Bacteria were grown to an OD₆₀₀ of 0.9, and autolysis was induced by 0.01% Triton X-100 (B), resulting in slightly quicker autolysis of the D39 ΔrafX mutant than the WT or complemented strain, or by 0.02% Triton X-100 (C), resulting in indistinguishable autolysis rates. Results are from three independent experiments (n = 3). Error bars indicate standard deviations. (D) Ultrastructures of S. pneumoniae WT and ΔrafX mutant D39 strains. Bacteria were harvested in the mid-exponential phase of growth and conventionally embedded in thin sections for examination by TEM. Bar, 2 (top) or 0.2 (bottom) μm.