Lipids activate SecA for high affinity binding to the SecYEG complex

Sabrina Koch, Janny G. de Wit, Iuliia Vos, Jan Peter Birkner, Pavlo Gordiichuk, Andreas Herrmann, Antoine M van Oijen, Arnold J.M. Driessen

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26 Citations (Scopus)
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Abstract

Protein translocation across the bacterial cytoplasmic membrane is an essential process catalyzed predominantly by the Sec translocase. This system consists of the membrane-embedded protein-conducting channel SecYEG, the motor ATPase SecA, and the heterotrimeric SecDFyajC membrane protein complex. Previous studies suggest that anionic lipids are essential for SecA activity and that the N-terminus of SecA is capable of penetrating the lipid bilayer. The role of lipid binding, however, has remained elusive. By employing differently sized nanodiscs reconstituted with single SecYEG complexes and comprising varying amounts of lipids, we establish that SecA gains access to the SecYEG complex via a lipid-bound intermediate state, whilst acidic phospholipids allosterically activate SecA for ATP-dependent protein translocation.

Original languageEnglish
Pages (from-to)22534-22543
Number of pages9
JournalThe Journal of Biological Chemistry
Volume291
Issue number43
Early online date9-Sep-2016
DOIs
Publication statusPublished - 21-Oct-2016

Keywords

  • DEPENDENT MANNER
  • ATPASE
  • COLI PLASMA-MEMBRANE
  • ESCHERICHIA-COLI
  • PROTEIN-TRANSLOCATION
  • IN-VIVO
  • NANOLIPOPROTEIN PARTICLES
  • PREPROTEIN TRANSLOCASE
  • PHOSPHOLIPID-BILAYER
  • ACIDIC PHOSPHOLIPIDS

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