Cryo-EM structure of respiratory complex I at work

Elife. 2018 Oct 2;7:e39213. doi: 10.7554/eLife.39213.

Abstract

Mitochondrial complex I has a key role in cellular energy metabolism, generating a major portion of the proton motive force that drives aerobic ATP synthesis. The hydrophilic arm of the L-shaped ~1 MDa membrane protein complex transfers electrons from NADH to ubiquinone, providing the energy to drive proton pumping at distant sites in the membrane arm. The critical steps of energy conversion are associated with the redox chemistry of ubiquinone. We report the cryo-EM structure of complete mitochondrial complex I from the aerobic yeast Yarrowia lipolytica both in the deactive form and after capturing the enzyme during steady-state activity. The site of ubiquinone binding observed during turnover supports a two-state stabilization change mechanism for complex I.

Keywords: Yarrowia lipolytica; active/deactive transition; molecular biophysics; redox-linked proton translocation; respiratory complex I; structural biology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cryoelectron Microscopy / methods
  • Crystallography, X-Ray
  • Electron Transport Complex I / chemistry
  • Electron Transport Complex I / metabolism*
  • Electron Transport Complex I / ultrastructure
  • Energy Metabolism
  • Fungal Proteins / chemistry
  • Fungal Proteins / metabolism*
  • Fungal Proteins / ultrastructure
  • Mitochondria / metabolism*
  • Mitochondria / ultrastructure
  • Models, Molecular
  • Oxidation-Reduction
  • Oxygen Consumption
  • Protein Conformation
  • Proton-Motive Force
  • Sequence Homology, Amino Acid
  • Yarrowia / genetics
  • Yarrowia / metabolism*
  • Yarrowia / ultrastructure

Substances

  • Fungal Proteins
  • Electron Transport Complex I