title: Comparative modeling of the H4-H5-loop of the alpha2-isoform of Na+/K+-ATPase alpha-subunit in the E1 conformation.
abstract: Restraint-based comparative modeling was used for calculation and visualization of the H4-H5-loop of Na+/K+-ATPase from mouse brain (Mus musculus, adult male brain, alpha2-isoform) between the amino acid residues Cys 336 and Arg 758 in the E1 conformation The structure consists of two well separated parts. The N-domain is formed by a seven-stranded antiparallel beta-sheet with two additional beta-strands and five alpha-helices sandwiching it, the P-domain is composed of a typical Rossman fold. The ATP-binding site was found on the N-domain to be identical in both alpha2- and alpha1-isoforms. The phosphorylation Asp 369 residue was found in the central part of the P-domain, located at the C-terminal end of the central beta-sheet. The distance between the alpha-carbon of Phe 475 at the ATP-binding site and the alpha-carbon of Asp 369 at the phosphorylation site is 3.22 nm. A hydrogen bond between the oxygen atom of Asp 369 and the nitrogen atom of Lys 690 was clearly detected and assumed to play a key role in maintaining the proper structure of the phosphorylaton site in E1 conformation.
authors.affiliation: Laboratory of Tissue Engineering, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: G
authors.initials: G
authors.lastname: Tejral
authors.forename: L
authors.initials: L
authors.lastname: Kolácná
authors.forename: A
authors.initials: A
authors.lastname: Kotyk
authors.forename: E
authors.initials: E
authors.lastname: Amler
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology*; D003196:Computer Graphics; D006860:Hydrogen Bonding; D021621:Imaging, Three-Dimensional; D007527:Isoenzymes / Q000737:chemistry; D008297:Male; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D015203:Reproducibility of Results; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D000255:Adenosine Triphosphate; C401838:Atp1a2 protein, mouse; D000254:Sodium-Potassium-Exchanging ATPase