NaCa2antiporters
NaCa2 antiporters are membrane proteins that catalyze the coupled exchange of two sodium ions (Na⁺) for one calcium ion (Ca²⁺) across biological membranes. They are part of the larger secondary transporter superfamily and are found in bacteria, archaea, and eukaryotic organisms, including plants. The antiport activity is driven by the electrochemical gradient of sodium, allowing the depletion of intracellular calcium or the import of calcium depending on the direction of transport. This exchange is important for maintaining ion homeostasis, regulating cellular signaling pathways, and supporting processes such as cell growth and stress responses.
The structural organization of NaCa2 antiporters typically consists of a core domain with 10–12 transmembrane helices
NaCa2 antiporters are present in several well-characterized families. In bacteria, the NcsB protein of Bacillus subtilis
Although structural data for many NaCa2 antiporters remain limited, cryo-electron microscopy and X-ray crystallography studies of