7qsk
Bovine complex I in lipid nanodisc, Active-Q10
Structural highlights
Function[Q7JAS9_BOVIN] Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) which catalyzes electron transfer from NADH through the respiratory chain, using ubiquinone as an electron acceptor. Essential for the catalytic activity of complex I.[ARBA:ARBA00024297][RuleBase:RU003640] Publication Abstract from PubMedMitochondrial complex I is a central metabolic enzyme that uses the reducing potential of NADH to reduce ubiquinone-10 (Q10) and drive four protons across the inner mitochondrial membrane, powering oxidative phosphorylation. Although many complex I structures are now available, the mechanisms of Q10 reduction and energy transduction remain controversial. Here, we reconstitute mammalian complex I into phospholipid nanodiscs with exogenous Q10. Using cryo-EM, we reveal a Q10 molecule occupying the full length of the Q-binding site in the 'active' (ready-to-go) resting state together with a matching substrate-free structure, and apply molecular dynamics simulations to propose how the charge states of key residues influence the Q10 binding pose. By comparing ligand-bound and ligand-free forms of the 'deactive' resting state (that require reactivating to catalyse), we begin to define how substrate binding restructures the deactive Q-binding site, providing insights into its physiological and mechanistic relevance. Cryo-EM structures define ubiquinone-10 binding to mitochondrial complex I and conformational transitions accompanying Q-site occupancy.,Chung I, Wright JJ, Bridges HR, Ivanov BS, Biner O, Pereira CS, Arantes GM, Hirst J Nat Commun. 2022 May 19;13(1):2758. doi: 10.1038/s41467-022-30506-1. PMID:35589726[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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