FIG. 1.

Western blots measuring the effect of the exoZ and exoH mutations on the extracellular accumulation of ExsH (by use of anti-ExsH polyclonal antibodies) (A) and ExoK (by use of anti-ExoK polyclonal antibodies) (B and C). The exoY, exoY exoZ, exoY exoH, and exoY exoH exoZ strains were cultivated in GMS medium (A, B) or in MGS medium (C) for a total of 5 days. Each lane contains a 5-μl aliquot of cell-free culture supernatant from day 1, day 3, or day 5 cultures. For blots A and C, the control lane corresponds to the negative control exoY exoK exsH strain. For blot B, the control lane corresponds to the exoY strain cultivated in MGS medium, which serves as a positive control for detection of extracellular ExoK. Each control sample corresponds to cell-free supernatants of a day 5 culture. Arrows indicate expected positions of ExsH and ExoK. Lines indicate positions of molecular weight markers (in kilodaltons).