FIG. 8.

The DC3000 ΔhrpP mutant secretes no other T3SS substrate. The wild-type DC3000, DC3000 ΔhrpP (CUCPB5453), and DC3000 ΔhrcQRSTU (CUCPB5113) strains were grown in HMM as described for Fig. 7. Supernatant proteins were separated first by isoelectric focusing on a pH-3 to -10 nonlinear gradient, followed by SDS-PAGE. Gels were stained with Sypro ruby protein stain (Bio-Rad) and visualized with UV light. One representative gel for each strain is shown. T3SS substrates secreted by DC3000 are indicated by the white circles.