title: Ion mobility-mass spectrometry of a rotary ATPase reveals ATP-induced reduction in conformational flexibility.
abstract: Rotary ATPases play fundamental roles in energy conversion as their catalytic rotation is associated with interdomain fluctuations and heterogeneity of conformational states. Using ion mobility mass spectrometry we compared the conformational dynamics of the intact ATPase from Thermus thermophilus with those of its membrane and soluble subcomplexes. Our results define regions with enhanced flexibility assigned to distinct subunits within the overall assembly. To provide a structural context for our experimental data we performed molecular dynamics simulations and observed conformational changes of the peripheral stalks that reflect their intrinsic flexibility. By isolating complexes at different phases of cell growth and manipulating nucleotides, metal ions and pH during isolation, we reveal differences that can be related to conformational changes in the Vo complex triggered by ATP binding. Together these results implicate nucleotides in modulating flexibility of the stator components and uncover mechanistic detail that underlies operation and regulation in the context of the holoenzyme.
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK.
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK.
authors.forename: Argyris
authors.initials: A
authors.lastname: Politis
authors.affiliation: The Victor Chang Cardiac Research Institute, Darlinghurst NSW 2010, Australia.|The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Roberta
authors.initials: R
authors.lastname: Davies
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK.
authors.forename: Idlir
authors.initials: I
authors.lastname: Liko
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK.
authors.forename: Kuan-Jung
authors.initials: KJ
authors.lastname: Wu
authors.affiliation: The Victor Chang Cardiac Research Institute, Darlinghurst NSW 2010, Australia.|The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Alastair G
authors.initials: AG
authors.lastname: Stewart
authors.affiliation: The Victor Chang Cardiac Research Institute, Darlinghurst NSW 2010, Australia.|The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Daniela
authors.initials: D
authors.lastname: Stock
authors.affiliation: Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, UK.
authors.forename: Carol V
authors.initials: CV
authors.lastname: Robinson
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D007477:Ions / Q000737:chemistry*; D013058:Mass Spectrometry; D008958:Models, Molecular; D008968:Molecular Conformation; D009711:Nucleotides
chemical_list: D007477:Ions; D009711:Nucleotides; D000251:Adenosine Triphosphatases