FIG 3.
RsiP levels decrease in the presence of cefoxitin. B. thuringiensis expressing tetracycline-inducible gfp-rsiP (EBT360) or empty vector (EV; EBT169) was subcultured 1:50 into LB supplemented with ATc (50 ng/ml). At mid-log phase, cells were incubated with 5 μg/ml of cefoxitin for various times (0, 15, 30, 60, 120, or 180 min) (A) or increasing concentrations of cefoxitin (0, 0.05, 0.5, 5, 50, or 500 μg/ml) for 1 h (B). The immunoblot was probed with antisera against RsiP (α-RsiP76–275). Streptavidin IR680LT was used to detect HD73_4231 (PycA homolog), which served as a loading control (62, 63). The color blot showing both anti-RsiP and streptavidin on a single gel is shown in Fig. S3. Numbers at right indicate molecular masses in kilodaltons.