6g72
Mouse mitochondrial complex I in the deactive state
Structural highlights
FunctionNU3M_MOUSE Core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) that is believed to belong to the minimal assembly required for catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone (By similarity). Publication Abstract from PubMedComplex I (NADH:ubiquinone oxidoreductase) uses the reducing potential of NADH to drive protons across the energy-transducing inner membrane and power oxidative phosphorylation in mammalian mitochondria. Recent cryo-EM analyses have produced near-complete models of all 45 subunits in the bovine, ovine and porcine complexes and have identified two states relevant to complex I in ischemia-reperfusion injury. Here, we describe the 3.3-A structure of complex I from mouse heart mitochondria, a biomedically relevant model system, in the 'active' state. We reveal a nucleotide bound in subunit NDUFA10, a nucleoside kinase homolog, and define mechanistically critical elements in the mammalian enzyme. By comparisons with a 3.9-A structure of the 'deactive' state and with known bacterial structures, we identify differences in helical geometry in the membrane domain that occur upon activation or that alter the positions of catalytically important charged residues. Our results demonstrate the capability of cryo-EM analyses to challenge and develop mechanistic models for mammalian complex I. Cryo-EM structures of complex I from mouse heart mitochondria in two biochemically defined states.,Agip AA, Blaza JN, Bridges HR, Viscomi C, Rawson S, Muench SP, Hirst J Nat Struct Mol Biol. 2018 Jun 18. pii: 10.1038/s41594-018-0073-1. doi:, 10.1038/s41594-018-0073-1. PMID:29915388[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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