Involved in the uptake of osmoprotectants. Can transport ectoine, proline and glycine betaine. Na(+) is probably the coupling ion. Optimum temperature is 25 degrees Celsius (irrespective of the state of osmotic stimulation). Constitutively expressed (PubMed:9811661). Induced upon hyperosmotic conditions, but the already high maximal uptake capacity is not further elevated, indicating that the amount of EctP is not changed (PubMed:17390131). Belongs to the BCCT transporter (TC 2.A.15) family.