title: ATP synthases from archaea: the beauty of a molecular motor.
abstract: Archaea live under different environmental conditions, such as high salinity, extreme pHs and cold or hot temperatures. How energy is conserved under such harsh environmental conditions is a major question in cellular bioenergetics of archaea. The key enzymes in energy conservation are the archaeal A1AO ATP synthases, a class of ATP synthases distinct from the F1FO ATP synthase ATP synthase found in bacteria, mitochondria and chloroplasts and the V1VO ATPases of eukaryotes. A1AO ATP synthases have distinct structural features such as a collar-like structure, an extended central stalk, and two peripheral stalks possibly stabilizing the A1AO ATP synthase during rotation in ATP synthesis/hydrolysis at high temperatures as well as to provide the storage of transient elastic energy during ion-pumping and ATP synthesis/-hydrolysis. High resolution structures of individual subunits and subcomplexes have been obtained in recent years that shed new light on the function and mechanism of this unique class of ATP synthases. An outstanding feature of archaeal A1AO ATP synthases is their diversity in size of rotor subunits and the coupling ion used for ATP synthesis with H(+), Na(+) or even H(+) and Na(+) using enzymes. The evolution of the H(+) binding site to a Na(+) binding site and its implications for the energy metabolism and physiology of the cell are discussed.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore. Electronic address: ggrueber@ntu.edu.sg.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Grüber
authors.affiliation: School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
authors.forename: Malathy Sony Subramanian
authors.initials: MS
authors.lastname: Manimekalai
authors.affiliation: Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Mayer
authors.affiliation: Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany. Electronic address: vmueller@bio.uni-frankfurt.de.
authors.forename: Volker
authors.initials: V
authors.lastname: Müller
mesh_terms: D001105:Archaea / Q000201:enzymology*; D019843:Archaeal Proteins / Q000737:chemistry / Q000502:physiology*; D001665:Binding Sites; D055162:Biocatalysis; D020134:Catalytic Domain; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry / Q000502:physiology*; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000502:physiology*
chemical_list: D019843:Archaeal Proteins; D020409:Molecular Motor Proteins; C474451:F1F0-ATP synthase; D025261:Mitochondrial Proton-Translocating ATPases
keywords: ATPase; Energy conservation; Methanogenesis; Na(+) bioenergetics; Rotary enzyme; c ring