FIG. 6.

The phosphoacceptor sites of PilG and PilH are required for function. (A) Subsurface TM assays of PAO1 (WT) and the ΔpilG, ΔpilG(comp), ΔpilH, ΔpilH(comp), His-tagged pilG (pilG-His), and pilH (pilH-His) mutants, as well as the His-tagged pilG and pilH point mutant strains PAO1ΔpilG(D58A)-His and PAO1ΔpilH(D52A)-His. Bar, 1 cm. (B) Graph depicting average TM zone diameters for the indicated strains. Shown are the means ± the SD (n = 5). The residual zone of TM in the pilG mutants represents colony growth and is similar to that of the ΔpilA mutant. (C) Surface structures (SS) and intracellular (WC) preparations of the indicated strains were immunoblotted with a polyclonal antibody to PilA (α-pilA) or to FliC (α-FliC), as described in Fig. 2.