title: The structure of Mg-ATPase nucleotide-binding domain at 1.6 A resolution reveals a unique ATP-binding motif.
abstract: The structure of the nucleotide-binding domain of the Mg-ATPase MgtA from Escherichia coli has been solved and refined to 1.6 A resolution. The structure is made up of a six-stranded beta-sheet and a bundle of three alpha-helices, with the nucleotide-binding site sandwiched in between. The MgtA nucleotide-binding domain is shorter and more compact compared with that of the related Ca-ATPase and lacks one of the beta-strands at the edge of the beta-sheet. The ATP-binding pocket is surrounded by three sequence and structural motifs known from other P-type ATPases and a fourth unique motif that is found only in Mg-ATPases. This motif consists of a short polypeptide stretch running very close to the ATP-binding site, while in Ca-ATPase the binding site is more open, with the corresponding polypeptide segment folded away from the active site.
authors.affiliation: Department of Biology, August Krogh Building, University of Copenhagen, DK-2100 Copenhagen O, Denmark. kohakansson@bio.ku.dk
authors.forename: Kjell O
authors.initials: KO
authors.lastname: Håkansson
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C490561:MgtA protein, E coli