title: On allosteric modulation of P-type Cu(+)-ATPases.
abstract: P-type ATPases perform active transport of various compounds across biological membranes and are crucial for ion homeostasis and the asymmetric composition of lipid bilayers. Although their functional cycle share principles of phosphoenzyme intermediates, P-type ATPases also show subclass-specific sequence motifs and structural elements that are linked to transport specificity and mechanistic modulation. Here we provide an overview of the Cu(+)-transporting ATPases (of subclass PIB) and compare them to the well-studied sarco(endo)plasmic reticulum Ca(2+)-ATPase (of subclass PIIA). Cu(+) ions in the cell are delivered by soluble chaperones to Cu(+)-ATPases, which expose a putative "docking platform" at the intracellular interface. Cu(+)-ATPases also contain heavy-metal binding domains providing a basis for allosteric control of pump activity. Database analysis of Cu(+) ligating residues questions a two-site model of intramembranous Cu(+) binding, and we suggest an alternative role for the proposed second site in copper translocation and proton exchange. The class-specific features demonstrate that topological diversity in P-type ATPases may tune a general energy coupling scheme to the translocation of compounds with remarkably different properties.
authors.affiliation: Centre for Membrane Pumps in Cells and Disease (PUMPkin), Danish National Research Foundation, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mattle
authors.forename: Oleg
authors.initials: O
authors.lastname: Sitsel
authors.forename: Henriette E
authors.initials: HE
authors.lastname: Autzen
authors.forename: Gabriele
authors.initials: G
authors.lastname: Meloni
authors.forename: Pontus
authors.initials: P
authors.lastname: Gourdon
authors.forename: Poul
authors.initials: P
authors.lastname: Nissen
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism*; D000494:Allosteric Regulation; D001665:Binding Sites; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D018360:Crystallography, X-Ray; D017136:Ion Transport; D008954:Models, Biological; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D011487:Protein Conformation
chemical_list: D027682:Cation Transport Proteins; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases