title: Structure-function relationship in P-type ATPases--a biophysical approach.
abstract: P-type ATPases are a large family of membrane proteins that perform active ion transport across biological membranes. In these proteins the energy-providing ATP hydrolysis is coupled to ion-transport that builds up or maintains the electrochemical potential gradients of one or two ion species across the membrane. P-type ATPases are found in virtually all eukaryotic cells and also in bacteria, and they are transporters of a broad variety of ions. So far, a crystal structure with atomic resolution is available only for one species, the SR Ca-ATPase. However, biochemical and biophysical studies provide an abundance of details on the function of this class of ion pumps. The aim of this review is to summarize the results of preferentially biophysical investigations of the three best-studied ion pumps, the Na,K-ATPase, the gastric H,K-ATPase, and the SR Ca-ATPase, and to compare functional properties to recent structural insights with the aim of contributing to the understanding of their structure-function relationship.
authors.affiliation: Department of Biology, University of Konstanz, Fach M635, 78457 Konstanz, Germany. h-j.apell@uni-konstanz.de
authors.forename: H-J
authors.initials: HJ
authors.lastname: Apell
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000502:physiology*; D000818:Animals; D001692:Biological Transport; D001703:Biophysics / Q000379:methods; D000252:Calcium-Transporting ATPases / Q000737:chemistry / Q000502:physiology; D004594:Electrophysiology; D017506:H(+)-K(+)-Exchanging ATPase / Q000737:chemistry / Q000502:physiology; D006801:Humans; D006868:Hydrolysis; D007477:Ions; D008956:Models, Chemical; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000502:physiology; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D007477:Ions; D000251:Adenosine Triphosphatases; D017506:H(+)-K(+)-Exchanging ATPase; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase