Figure 2. Role of PilV and PilX in pilus biogenesis.

1. ELISA analysis of surface-exposed pilin in the pilV mutant and complemented strains. Results are presented relative to the wild-type strain, given the value of 1.
2. ELISA analysis of surface-exposed pilin in the pilX mutant.
3. ELISA analysis of surface-exposed pilin in the pilVpilX double mutant.
4. Immunofluorescence analysis of pili on the surface of the indicated bacterial strains. DAPI is in blue and pilus staining in green (20D9).
5. Quantitative determination of the number of pili detected per individual diplococcus. The results of 3 independent experiments each with over 50 bacteria are included.
6. Frequency distribution of the number of pili per diplococcus expressed by the wild-type strain (black line), the pilV strain (blue line), and the pilX strain (red line).
7. Pili length measurement (μm). The results of 3 independent experiments each with over 50 bacteria are included.
8. Frequency distribution of the length of pili expressed by the wild-type, pilV and the pilX strains (same color code as in F).
9. A typical track representing bacterial movement resulting from twitching motility over a 2-min period.
10. Frequency representation of the different speeds of bacteria for the wild-type, pilV and pilX strains (same color code as in F).

Data information: Data represent mean ± SEM; ^*P ≤ 0.05; ^****P ≤ 0.001.