Fig. 3.

Calcium accumulation in mycobacterial cells. A) Hypothesized function of CtpF in the mycobacterial plasma membrane. In the presence of a high extracellular calcium concentration, CtpF transports calcium against its concentration gradient. B) Calcium accumulation inside M. smegmatis WT and the recombinant cells expressing CtpF. The amount of calcium accumulated was internally normalized against the amount of calcium measured in the dry mass of pellet from the WT strain. C) Sodium accumulation in the absence and presence of potassium in the WT and recombinant strains normalized with respect to the metal accumulation in the WT strain. D) Calcium accumulation in Mtb cells. The amount of calcium accumulated was internally normalized against the amount of calcium measured in the dry mass of pellet from the WT strain. The data shown are representative of three independent experiments. Unpaired two-tailed t test, ****P < 0.0001.