title: Eight amino acids form the ATP recognition site of Na(+)/K(+)-ATPase.
abstract: Point mutations of a part of the H(4)-H(5) loop (Leu(354)-Ile(604)) of Na(+)/K(+)-ATPase have been used to study the ATP and TNP-ATP binding affinities. Besides the previously reported amino acid residues Lys(480), Lys(501), Gly(502), and Cys(549), we have found four more amino acid residues, viz., Glu(446), Phe(475), Gln(482), and Phe(548), completing the ATP-binding pocket of Na(+)/K(+)-ATPase. Moreover, mutation of Arg(423) has also resulted in a large decrease in the extent of ATP binding. This residue, localized outside the binding pocket, seems to play a key role in supporting the proper structure and shape of the binding site, probably due to formation of a hydrogen bond with Glu(472). On the other hand, only some minor effects were caused by mutations of Ile(417), Asn(422), Ser(445), and Glu(505).
authors.affiliation: Institute of Physiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 14220 Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Kubala
authors.forename: Jan
authors.initials: J
authors.lastname: Teisinger
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Ettrich
authors.forename: Katerina
authors.initials: K
authors.lastname: Hofbauerová
authors.forename: Vladimír
authors.initials: V
authors.lastname: Kopecký
authors.forename: Vladimír
authors.initials: V
authors.lastname: Baumruk
authors.forename: Rita
authors.initials: R
authors.lastname: Krumscheid
authors.forename: Jaromír
authors.initials: J
authors.lastname: Plásek
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Schoner
authors.forename: Evzen
authors.initials: E
authors.lastname: Amler
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D003545:Cysteine / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D018698:Glutamic Acid / Q000737:chemistry; D005973:Glutamine / Q000737:chemistry; D006860:Hydrogen Bonding; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D010649:Phenylalanine / Q000737:chemistry; D017354:Point Mutation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000596:Amino Acids; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D005973:Glutamine; D018698:Glutamic Acid; D010649:Phenylalanine; D000255:Adenosine Triphosphate; D000254:Sodium-Potassium-Exchanging ATPase; D003545:Cysteine