Crystal Structure of Na + , K + -ATPase in the Na + -Bound State

• DOI: 10.1126/science.1243352
• Publication Date: 2013-09-20T08:45:23Z
• Authors: Maria Nyblom; Hanne Poulsen; Pontus Gourdon; Linda Reinhard; Magnus Andersson; Erik Lindahl; Natalya Fedosova; Poul Nissen
• Keywords: Models, Molecular; 0301 basic medicine; Swine; Cell Membrane; Sodium; Crystallography, X-Ray; Protein Structure, Secondary; Protein Structure, Tertiary; 03 medical and health sciences; Mutation; Animals; Sodium-Potassium-Exchanging ATPase; Protein Binding

Pumping Out Sodium

Mammalian cells contain relatively high concentrations of potassium but low concentrations of sodium. This balance is maintained by an ion pump, the Na + , K + –adenosine triphosphatase, in an adenosine triphosphate–driven transport cycle that results in the export of three sodium ions and the import of two potassium ions. Structures of potassium-bound conformations of the pump have been determined. Now,

Nyblom et al.

(p. 123 , published online 19 September) report on the high-resolution crystal structure of a Na + -bound conformation, which reveals conformational changes associated with Na + binding.