FIG 4.
Altered YpeB proteolysis does not slow spore germination and outgrowth. Decoated ΔypeB (▲), YpeBT202E/S203L-His6 (□), YpeBA168E/S169L-His6 (◆), YpeBA168E/S169L, T202E/S203L-His6 (×), and YpeB-His6 (●) B. anthracis spores were heat activated and germinated in BHI medium at 37°C; germination and outgrowth were tracked as changes in OD. Decoating of spores eliminates CwlJ activity, and thus, completion of germination is dependent on YpeB for maintenance of SleB activity in the spores (18). The data shown are averages of results from three independent spore preparations; error bars are omitted for clarity. Germination of YpeBT202E/S203L-His6, YpeBA168E/S169L-His6, and YpeBA168E/S169L, T202E/S203L-His6 spores is not significantly different (P > 0.06) at any time point. Likewise, germination of YpeB-His6 and YpeBT202E/S203L-His6 spores is not significantly different (P > 0.07) at any time point. Focusing on stage 2 of germination, from 45 to 95 min (18), YpeBA168E/S169L-His6 and YpeB-His6 spores do not significantly differ (P > 0.07), whereas YpeBA168E/S169L, T202E/S203L-His6 and YpeB-His6 spores are not significantly different (P > 0.05) except from 75 to 80 min (P < 0.05).