Figure 7. Schematic representation of the impact of the amount of type IV pili on the different functions mediated by these organelles.

The top part of the schematic indicates the efficiency of the different pili-mediated properties as a function of bulk amount of pili and number of pili per bacterium. In the bottom part of the schematic, representative situations are depicted: (i) In the absence of pili, no related function is observed; (ii) A single pilus is required for competence; (iii) A minimum of 2 pili is necessary for aggregation; (iv) About 5 pili per bacterium are necessary for optimal bacteria-induced plasma membrane reshaping. Pili from neighboring bacteria are indicated as a dotted line.