Part of the tripartite ATP-independent periplasmic (TRAP) transport system TeaABC involved in the uptake of ectoine and hydroxyectoine in response to osmotic upshock. Probably functions as a recovery system for synthesized ectoine that leaks out of the cell. Binds ectoine with high affinity. Affinity for hydroxyectoine is approximately 20-fold lower. Monomer. The complex comprises the extracytoplasmic solute receptor protein TeaA, and the two transmembrane proteins TeaB and TeaC. Deletion abolishes accumulation of ectoine from the medium. The ectoine/TeaA complex displays a closed conformation (PubMed:18702523). Interaction with the transmembrane proteins induces opening of TeaA, which facilitates substrate release (PubMed:22084072). Belongs to the bacterial solute-binding protein 7 family.