FIGURE 3.
Functional analysis of OutC and OutD point mutants. The secretion activity of OutC and OutD mutants (indicated on top of gels) was estimated in a complementation assays with D. dadantii strains A3656 ΔoutC (A and C) and A3658 ΔoutD (B). Bacteria carrying a plasmid with mutant alleles of either outC (A), or outD (B), or outC and outD (C) were grown to steady-state; then, culture supernatant (S) and cells (C) were separated and analyzed by immunoblotting with PelD and PelI antibodies. The amount of secreted proteins (PelD, PelE, and PelI) in culture supernatant reflects secretion efficiency. The abundance of the corresponding OutC and OutD variants is shown on Fig. 4.