Structural basis for Ca2+ regulation in the Na+/Ca2+ exchanger.

  title={Structural basis for Ca2+ regulation in the Na+/Ca2+ exchanger.},
  author={Mark Hilge and Jan M A Aelen and Anastassis Perrakis and Geerten W. Vuister},
  journal={Annals of the New York Academy of Sciences},
Binding of Na+ and Ca2+ ions to the large cytosolic loop of the Na+/Ca2+ exchanger (NCX) regulates its ion transport across the plasma membrane. We determined the solution structures of two Ca2+-binding domains (CBD1 and CBD2) that, together with an alpha-catenin-like domain (CLD) form the regulatory exchanger loop. CBD1 and CBD2 constitute a novel Ca2+-binding motif and are very similar in the Ca2+-bound state. Strikingly, in the absence of Ca2+ the upper half of CBD1 unfolds while CBD2… CONTINUE READING