title: The crystallographic structure of Na,K-ATPase N-domain at 2.6A resolution.
abstract: The structure of the N-domain of porcine alpha(2) Na,K-ATPase was determined crystallographically to 3.2A resolution by isomorphous heavy-atom replacement using a single mercury derivative. The structure was finally refined against 2.6A resolution synchrotron data. The domain forms a seven-stranded antiparallel beta-sheet with two additional beta-strands forming a hairpin and five alpha-helices. Approximately 75% of the residues were superimposable with residues from the structure of Ca-ATPase N-domain, and a structure-based sequence alignment is presented. The positions of key residues are discussed in relation to the pattern of hydrophobicity, charge and sequence conservation of the molecular surface. The structure of a hexahistidine tag binding to nickel ions is presented.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray; D007477:Ions; D008628:Mercury / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D020033:Protein Isoforms; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry*; D013552:Swine; D017356:Synchrotrons
chemical_list: D007477:Ions; D020033:Protein Isoforms; D000254:Sodium-Potassium-Exchanging ATPase; D008628:Mercury