title: Attempts to define distinct parts of NADH:ubiquinone oxidoreductase (complex I).
abstract: The NADH:ubiquinone oxidoreductase (complex I) is made up of a peripheral part and a membrane part. The two parts are arranged perpendicular to each other and give the complex an unusual L-shaped structure. The peripheral part protrudes into the matrix space and constitutes the proximal segment of the electron pathway with the NADH-binding site, the FMN and at least three iron-sulfur clusters. The membrane part constitutes the distal segment of the electron pathway with at least one iron-sulfur cluster and the ubiquinone-binding site. Both parts are assembled separately and relationships of the major structural modules of the two parts with different bacterial enzymes suggest, that both parts also emerged independently in evolution. This assumption is further supported by the conserved order of bacterial complex I genes, which correlates with the topological arrangement of the corresponding subunits in the two parts of complex I.
authors.affiliation: Heinrich-Heine-Universität Düsseldorf, Institut für Biochemie, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Friedrich
authors.forename: U
authors.initials: U
authors.lastname: Weidner
authors.forename: U
authors.initials: U
authors.lastname: Nehls
authors.forename: W
authors.initials: W
authors.lastname: Fecke
authors.forename: R
authors.initials: R
authors.lastname: Schneider
authors.forename: H
authors.initials: H
authors.lastname: Weiss
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D005075:Biological Evolution; D002417:Cattle; D004579:Electron Transport; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000648:ultrastructure; D005798:Genes, Bacterial; D008854:Microscopy, Electron; D008929:Mitochondria, Heart / Q000201:enzymology; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000648:ultrastructure; D010231:Paracoccus denitrificans / Q000201:enzymology / Q000235:genetics; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; D016660:NAD(P)H Dehydrogenase (Quinone)