A Different Conformation for EGC Stator Subcomplex in Solution and in the Assembled Yeast V-ATPase: Possible Implications for Regulatory Disassembly

Meikel Diepholz, David Venzke, Simone Prinz, Claire Batisse, Beate Floerchinger, Manfred Roessle, Dmitri I. Svergun, Bettina Boettcher, James Fethiere

Research output: Contribution to journalArticlepeer-review

Abstract

Vacuolar ATPases (V-ATPases) are ATP-dependent proton pumps that maintain the acidity of cellular compartments. They are composed of a membrane-integrated proton-translocating V-0 and an extrinsic cytoplasmic catalytic domain V-1, joined by several connecting subunits. To clarify the arrangement of these peripheral connections and their interrelation with other subunits of the holocomplex, we have determined the solution structures of isolated EG and EGC connecting subcomplexes by small angle X-ray scattering and the 3D map of the yeast V-ATPase by electron microscopy. In solution, EG forms a slightly kinked rod, which assembles with subunit C into an L-shaped structure. This model is supported by the microscopy data, which show three copies of EG with two of these linked by subunit C. However, the relative arrangement of the EG and C subunits in solution is more open than that in the holoenzyme, suggesting a conformational change of EGC during regulatory assembly and disassembly.

Original languageEnglish
Pages (from-to)1789-1798
Number of pages10
JournalStructure
Volume16
Issue number12
DOIs
Publication statusPublished - 10 Dec 2008

Keywords

  • CELLBIO
  • PROTEINS

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