FIG. 5.

Growth rate-dependent variation in FIS levels in wild-type and rpoCΔ215–220 strains. (A) Western blot with anti-FIS antibody. Lanes 1 to 6, 40, 20, 10, 5, 2.5, and 1.25 ng of purified FIS protein, respectively. Lanes 7 to 10, protein extracts from the wild-type strain grown at 0.56, 0.85, 0.93, and 1.32 doublings/h, respectively. Lanes 11 to 14, protein extracts from the rpoCΔ215–220 strain grown at 0.59, 0.88, 0.96, and 1.12 doublings/h, respectively. Aliquots of lysates representing equivalent numbers of cells (as determined from the optical density) were loaded in each lane. (B) Amounts of FIS as a function of growth rate. Quantitation is illustrated for two independent experiments, including the one pictured in panel A, lanes 7 to 14, using the purified standards of FIS protein in lanes 1 to 6 for calibration.