Editor's Summary
13 December 2007
Pumping ions
P-type ATPases are cation pumps of fundamental importance for all eukaryotes and many prokaryotes. Three papers this week present structural and functional studies of key members of this superfamily. The cover shows the Na+,K+-pump structure, described at 3.5 Å resolution by Morth et al., together with J. C. Skou's original notes on his discovery of its Na+- and K+-dependent ATPase activity 50 years ago. The paper reveals the potassium-bound state and hints at a voltage-dependent basis of regulation, in part through kinetic experiments similar to Skou's. Olesen et al. have obtained crystallographic snapshots of the sarcoplasmic reticulum Ca2+-ATPase, the calcium pump, complemented by functional studies, and a complete mechanism of calcium transport is finally presented. In plants and fungi, cellular ion homeostasis and membrane potential are powered by the plasma membrane H+-ATPase — another P-type ATPase. Pedersen et al. present its X-ray structure and provide insight into how it pumps protons against a steep electrochemical gradient.
News and Views: Structural biology: Ion pumps made crystal clear
The function of every cell in our bodies depends on the work of proteins known as ion pumps. Several new crystal structures cast fresh light on how three different pumps deal with their distinct cargoes of ions.
David C. Gadsby
doi:10.1038/450957a
Article: The structural basis of calcium transport by the calcium pump
Claus Olesen, Martin Picard, Anne-Marie Lund Winther, Claus Gyrup, J. Preben Morth, Claus Oxvig, Jesper Vuust Møller & Poul Nissen
doi:10.1038/nature06418
Abstract | Full Text | PDF (1,340K) | Supplementary information
Article: Crystal structure of the sodium–potassium pump
J. Preben Morth, Bjørn P. Pedersen, Mads S. Toustrup-Jensen, Thomas L.-M. Sørensen, Janne Petersen, Jens Peter Andersen, Bente Vilsen & Poul Nissen
doi:10.1038/nature06419
Abstract | Full Text | PDF (1,688K) | Supplementary information
Letter: Crystal structure of the plasma membrane proton pump
Bjørn P. Pedersen, Morten J. Buch-Pedersen, J. Preben Morth, Michael G. Palmgren & Poul Nissen
doi:10.1038/nature06417
First paragraph | Full Text | PDF (877K) | Supplementary information