FIG 3.

B. anthracis SleB and YpeB are each degraded during spore formation in the absence of the partner protein. Wild-type (WT), ΔsleB, ΔypeB, and ypeB complementation (ypeB⁺) strains were grown in modified G broth at 37°C, and samples collected during sporulation were used for Western blot analysis. The designations t₂ through t₆ represent the numbers of hours since the initiation of sporulation. (A) Sporangia probed with anti-SleB antibodies. (B) Sporangia probed with anti-YpeB antibodies. (C) Sporangia from the ΔsleB strain probed with anti-YpeB antibodies. The positions of molecular size marker proteins (not shown), in kilodaltons, are indicated on the left.