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Mitochondrial complex I structure reveals ordered water molecules for catalysis and proton translocation
1The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
Nature Structural & Molecular Biology
|August 5, 2020
Summary
This study reveals the 2.7-Å structure of yeast mitochondrial complex I, detailing proton pathways crucial for ATP synthesis and understanding the
Area of Science:
- Biochemistry
- Structural Biology
- Mitochondrial Biology
Background:
- Mitochondrial complex I is essential for ATP synthesis via oxidative phosphorylation.
- Recent cryo-electron microscopy (cryo-EM) studies have advanced understanding of complex I structures and functions.
- Complex I plays a critical role in cellular energy metabolism and is implicated in various diseases.
Purpose of the Study:
- To determine the high-resolution structure of the 42-subunit complex I from Yarrowia lipolytica.
- To elucidate the proton-relay pathway involved in ubiquinone reduction.
- To investigate structural changes related to the mammalian complex I 'deactive transition' and its implications.
Main Methods:
- Cryo-electron microscopy (cryo-EM) at 2.7-Å resolution.
- Structural analysis of the Yarrowia lipolytica complex I.
- Comparative structural analysis with mammalian and yeast complex I structures.
Main Results:
- A detailed 2.7-Å structure of the 42-subunit Yarrowia lipolytica complex I was determined.
- A proton-relay pathway for ubiquinone reduction was identified, involving structured water molecules.
- Structural insights into the mammalian 'deactive transition' and its impact on the ubiquinone-binding site were gained.
Conclusions:
- The high-resolution structure provides critical insights into the catalytic mechanism of mitochondrial complex I.
- Understanding proton translocation pathways and the deactive transition mechanism is vital for comprehending cellular respiration and disease.
- This work advances mechanistic knowledge of this key respiratory enzyme.
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