title: A scaffold of accessory subunits links the peripheral arm and the distal proton-pumping module of mitochondrial complex I.
abstract: Mitochondrial NADH:ubiquinone oxidoreductase (complex I) is a very large membrane protein complex with a central function in energy metabolism. Complex I from the aerobic yeast Yarrowia lipolytica comprises 14 central subunits that harbour the bioenergetic core functions and at least 28 accessory subunits. Despite progress in structure determination, the position of individual accessory subunits in the enzyme complex remains largely unknown. Proteomic analysis of subcomplex Iδ revealed that it lacked eleven subunits, including the central subunits ND1 and ND3 forming the interface between the peripheral and the membrane arm in bacterial complex I. This unexpected observation provided insight into the structural organization of the connection between the two major parts of mitochondrial complex I. Combining recent structural information, biochemical evidence on the assignment of individual subunits to the subdomains of complex I and sequence-based predictions for the targeting of subunits to different mitochondrial compartments, we derived a model for the arrangement of the subunits in the membrane arm of mitochondrial complex I.
authors.affiliation: Medical School, Center for Membrane Proteomics, Goethe-University, Frankfurt am Main, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Angerer
authors.forename: Klaus
authors.initials: K
authors.lastname: Zwicker
authors.forename: Zibiernisha
authors.initials: Z
authors.lastname: Wumaier
authors.forename: Lucie
authors.initials: L
authors.lastname: Sokolova
authors.forename: Heinrich
authors.initials: H
authors.lastname: Heide
authors.forename: Mirco
authors.initials: M
authors.lastname: Steger
authors.forename: Silke
authors.initials: S
authors.lastname: Kaiser
authors.forename: Esther
authors.initials: E
authors.lastname: Nübel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Brutschy
authors.forename: Michael
authors.initials: M
authors.lastname: Radermacher
authors.forename: Ulrich
authors.initials: U
authors.lastname: Brandt
authors.forename: Volker
authors.initials: V
authors.lastname: Zickermann
mesh_terms: D042967:Electron Transport Complex I / Q000737:chemistry*; D008928:Mitochondria / Q000201:enzymology; D008958:Models, Molecular; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism; D017494:Proton Pumps / Q000737:chemistry*; D025062:Yarrowia / Q000201:enzymology
chemical_list: D021122:Protein Subunits; D017494:Proton Pumps; D042967:Electron Transport Complex I