Functional and structural asymmetry suggest a unifying principle for catalysis in membrane-bound pyrophosphatases

EMBO Reports, vol. 25, pp. 853–875

Abstract

Abstract Membrane-bound pyrophosphatases (M-PPases) are homodimeric primary ion pumps that couple the transport of Na + - and/or H + across membranes to the hydrolysis of pyrophosphate. Their role in the virulence of protist pathogens like Plasmodium falciparum makes them an intriguing target for structural and functional studies. Here, we show the first structure of a K + -independent M-PPase, asymmetric and time-dependent substrate binding in time-resolved structures of a K + -dependent M-PPase and demonstrate pumping-before-hydrolysis by electrometric studies. We suggest how key residues in helix 12, 13, and the exit channel loops affect ion selectivity and K + -activation due to a complex interplay of residues that are involved in subunit-subunit communication. Our findings not only explain ion selectivity in M-PPases but also why they display half-of-the-sites reactivity. Based on this, we propose, for the first time, a unified model for ion-pumping, hydrolysis, and energy coupling in all M-PPases, including those that pump both Na + and H + .

Authors 12

1. Jannik Strauss

   University of Leeds

   Affiliation as printed

   Astbury Centre for Structural and Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK

   Numaferm GmbH, Düsseldorf, Germany

   Astbury Centre for Structural and Molecular BiologyUniversity of Leeds LS2 9JT Leeds UK

   Numaferm GmbH Düsseldorf Germany

2. Craig Wilkinson

   University of Leeds

   Affiliation as printed

   Astbury Centre for Structural and Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK

   Astbury Centre for Structural and Molecular BiologyUniversity of Leeds LS2 9JT Leeds UK

3. Keni Vidilaseris

   University of Helsinki

   Affiliation as printed

   Molecular and Integrative Biosciences, Biological and Environmental Sciences, University of Helsinki, 00100, Helsinki, Finland

   Molecular and Integrative Biosciences, Biological and Environmental SciencesUniversity of Helsinki 00100 Helsinki Finland

4. Orquídea Ribeiro

   University of Helsinki

   Affiliation as printed

   Molecular and Integrative Biosciences, Biological and Environmental Sciences, University of Helsinki, 00100, Helsinki, Finland

   Molecular and Integrative Biosciences, Biological and Environmental SciencesUniversity of Helsinki 00100 Helsinki Finland

5. Jianing Liu

   University of Helsinki

   Affiliation as printed

   Molecular and Integrative Biosciences, Biological and Environmental Sciences, University of Helsinki, 00100, Helsinki, Finland

   Molecular and Integrative Biosciences, Biological and Environmental SciencesUniversity of Helsinki 00100 Helsinki Finland

6. James Hillier

   University of Leeds · Bio-Rad (United Kingdom)

   Affiliation as printed

   Astbury Centre for Structural and Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK

   Bio-Rad Laboratories Ltd., Watford, UK

   Astbury Centre for Structural and Molecular BiologyUniversity of Leeds LS2 9JT Leeds UK

   Bio-Rad Laboratories Ltd. Watford UK

7. Maximilian Wichert Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, University Leiden, PO Box 9502, 2300 RA, Leiden, The Netherlands

   Leiden Institute of ChemistryUniversity Leiden PO Box 9502 2300 RA Leiden The Netherlands

8. Anssi M. Malinen

   University of Turku

   Affiliation as printed

   Department of Life Technologies, University of Turku, FIN-20014, Turku, Finland

   Department of Life TechnologiesUniversity of Turku FIN‐20014 Turku Finland

9. Bernadette Gehl

   University of Helsinki · Aalto University

   Affiliation as printed

   Department of Applied Physics, Aalto University, FI-00076, AALTO, Espoo, Finland

   Molecular and Integrative Biosciences, Biological and Environmental Sciences, University of Helsinki, 00100, Helsinki, Finland

   Department of Applied PhysicsAalto University FI-00076, AALTO Espoo Finland

   Molecular and Integrative Biosciences, Biological and Environmental SciencesUniversity of Helsinki 00100 Helsinki Finland

10. Lars J. C. Jeuken Aachen

    Leiden University

    Affiliation as printed

    Leiden Institute of Chemistry, University Leiden, PO Box 9502, 2300 RA, Leiden, The Netherlands

    Leiden Institute of ChemistryUniversity Leiden PO Box 9502 2300 RA Leiden The Netherlands

11. Arwen R. Pearson

    Universität Hamburg · Hamburg Centre for Ultrafast Imaging

    Affiliation as printed

    Institute for Nanostructure and Solid State Physics, Hamburg Centre for Ultrafast Imaging, Universität Hamburg, 22761, Hamburg, Germany

    Institute for Nanostructure and Solid State PhysicsHamburg Centre for Ultrafast Imaging, Universität Hamburg 22761 Hamburg Germany

12. Adrian Goldman corresponding

    University of Leeds · University of Helsinki

    Affiliation as printed

    Astbury Centre for Structural and Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK. adrian.goldman@helsinki.fi

    Molecular and Integrative Biosciences, Biological and Environmental Sciences, University of Helsinki, 00100, Helsinki, Finland. adrian.goldman@helsinki.fi

    Astbury Centre for Structural and Molecular BiologyUniversity of Leeds LS2 9JT Leeds UK

    Molecular and Integrative Biosciences, Biological and Environmental SciencesUniversity of Helsinki 00100 Helsinki Finland