LcoP, an Osmoregulated Betaine/ectoine Uptake System from Corynebacterium Glutamicum

In Corynebacterium glutamicum, four uptake systems for compatible solutes have been characterized so far. DHPE (DeltabetPDeltaputPDeltaproPDeltaectP), a derivative of the C. glutamicum type strain ATCC 13032 carrying deletions in the corresponding genes, still showed a low betaine uptake rate of 1.4 nmol/(min mg cdm). Genome analyses revealed the presence of a putative carrier, named low capacity osmoregulated permease (LcoP), which shows similarities to compatible solute transporters of the betaine/carnitine/choline transporter (BCCT)-family. Deletion of lcoP in DHPE resulted in betaine and ectoine uptake deficiency. LcoP, a betaine and ectoine permease is regulated at the expression and the activity level by the external osmolality. Addition of local anesthetics modulated the activity of BCCT-family members BetP, EctP, and LcoP in a different manner, indicating a different type of lipid-protein interaction.