Role of the N-terminal signal peptide in the membrane insertion of Aquifex aeolicus F1F0 ATP synthase c-subunit

Authors

  • Chunli Zhang,

    1. Max Planck Institute of Biophysics, Department of Molecular Membrane Biology, Frankfurt am Main, Germany
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  • Marco Marcia,

    1. Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
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  • Julian D. Langer,

    1. Max Planck Institute of Biophysics, Department of Molecular Membrane Biology, Frankfurt am Main, Germany
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  • Guohong Peng,

    Corresponding author
    1. Max Planck Institute of Biophysics, Department of Molecular Membrane Biology, Frankfurt am Main, Germany
    2. Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
    • Correspondence

      G. Peng, Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max von Laue Strasse 3, D-60438 Frankfurt am Main, Germany

      Fax: +49 69 6303 1002

      Tel: +49 69 6303 1016

      E-mail: guohong.peng@biophys.mpg.de

      H. Michel, Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max von Laue Strasse 3, D-60438 Frankfurt am Main, Germany

      Fax: +49 69 6303 1002

      Tel: +49 69 6303 1001

      E-mail: hartmut.michel@biophys.mpg.de

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  • Hartmut Michel

    Corresponding author
    1. Max Planck Institute of Biophysics, Department of Molecular Membrane Biology, Frankfurt am Main, Germany
    • Correspondence

      G. Peng, Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max von Laue Strasse 3, D-60438 Frankfurt am Main, Germany

      Fax: +49 69 6303 1002

      Tel: +49 69 6303 1016

      E-mail: guohong.peng@biophys.mpg.de

      H. Michel, Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max von Laue Strasse 3, D-60438 Frankfurt am Main, Germany

      Fax: +49 69 6303 1002

      Tel: +49 69 6303 1001

      E-mail: hartmut.michel@biophys.mpg.de

    Search for more papers by this author

Abstract

Rotary ATPases are membrane protein complexes that couple ATP hydrolysis to ion translocation across the membrane. Overall, they are evolutionarily well conserved, but the N-terminal segments of their rotary subunits (c-subunits) possess different lengths and levels of hydrophobicity across species. By analyzing the N-terminal variability, we distinguish four phylogenetic groups of c-subunits (groups 1–4). We characterize a member of group 2, the c-subunit from Aquifex aeolicus F1F0 ATP synthase, both in native cells and in a heterologous expression system. We demonstrate that its N-terminal segment forms a signal peptide with signal recognition particle (SRP) recognition features and is obligatorily required for membrane insertion. Based on our study and on previous characterizations of c-subunits from other organisms, we propose that c-subunits follow different membrane insertion pathways.

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