FIGURE 1.

In trans complementation of pilQ deletion mutant HB27 ΔpilQ::bleo. A, the pilQ gene was amplified by PCR and cloned into pDM12 using restriction sites NdeI and NotI. The resulting plasmid pDM12-pilQhis-Q was electroporated into HB27 ΔpilQ::bleo. B, crude extracts of HB27 wild type (lane WT), HB27 ΔpilQ::bleo (lane ΔQ), and HB27 ΔpilQ::bleo carrying pDM12-pilQhis-Q (lane Q) were subjected to 3–12% polyacrylamide gradient SDS-PAGE followed by Western blot analysis. C, scheme of the putative secondary structure of PilQ and corresponding primer binding sites for the generation of N-terminal PilQ deletion derivatives by SDM using pDM12-pilQhis-Q as the template vector. The first maintained amino acid residues after SDM are indicated. Black boxes, α-helical domains; white boxes, β-sheets; aa, amino acid residues.