Cryo-EM structures of mitochondrial respiratory complex I from Drosophila melanogaster
- University of Cambridge, United Kingdom
Abstract
Respiratory complex I powers ATP synthesis by oxidative phosphorylation, exploiting the energy from NADH oxidation by ubiquinone to drive protons across an energy-transducing membrane. Drosophila melanogaster is a candidate model organism for complex I due to its high evolutionary conservation with the mammalian enzyme, well-developed genetic toolkit, and complex physiology for studies in specific cell types and tissues. Here, we isolate complex I from Drosophila and determine its structure, revealing a 43-subunit assembly with high structural homology to its 45-subunit mammalian counterpart, including a hitherto unknown homologue to subunit NDUFA3. The major conformational state of the Drosophila enzyme is the mammalian-type 'ready-to-go' active resting state, with a fully ordered and enclosed ubiquinone-binding site, but a subtly altered global conformation related to changes in subunit ND6. The mammalian-type 'deactive' pronounced resting state is not observed: in two minor states the ubiquinone-binding site is unchanged, but a deactive-type p-bulge is present in ND6-TMH3. Our detailed structural knowledge of Drosophila complex I provides a foundation for new approaches to disentangle mechanisms of complex I catalysis and regulation in bioenergetics and physiology.
Data availability
Structural data have been deposited in the EMDB and PDB databases under the following accession codes: EMD-15936 and 8B9Z (Dm1; active), EMD-15937 and 8BA0 (Dm2; twisted), and EMD-15938 (Dm3; cracked).
Article and author information
Author details
Alvaro Sanchez-Martinez
Alexander J Whitworth
Funding
Medical Research Council (MC_UU_00015/6)
- Alexander J Whitworth
Medical Research Council (MC_UU_00028/6)
- Alexander J Whitworth
Medical Research Council (MC_UU_00015/2)
- Judy Hirst
Medical Research Council (MC_UU_00028/1)
- Judy Hirst
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Agip et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Cryo-EM structures of mitochondrial respiratory complex I from Drosophila melanogaster
eLife 12:e84424.
https://doi.org/10.7554/eLife.84424
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