FIG 8 .
Schematic representation of the SHP/RovS cell-to-cell communication mechanism. The SHP pheromone is produced as the precursor (I), maturated mainly by the Eep membrane-associated peptidase, and secreted into the extracellular medium via the PptAB transporter (II). Mature SHP from nt 15 to 23 (SHP15–23) is accumulated outside the cell (III) to be imported back into the cell by the oligopeptide transporter OppA1-F (IV). Finally, SHP15–23 interacts with RovS to positively regulate the transcription of the shp and gbs1556 genes (V), which are cotranscribed.