Characterization of the 9.5-kDa ubiquinone-binding protein of NADH:ubiquinone oxidoreductase (complex I) from Neurospora crassa

Biochemistry ◽  
1992 ◽  
Vol 31 (46) ◽  
pp. 11420-11424 ◽  
Author(s):  
Helga Heinrich ◽  
Jorge E. Azevedo ◽  
Sigurd Werner
Keyword(s):  
Neurospora Crassa ◽  
Complex I ◽  
Binding Protein ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Ubiquinone Binding

Mutants of Chlamydomonas reinhardtii Deficient in Mitochondrial Complex I: Characterization of Two Mutations Affecting the nd1 Coding Sequence

Genetics ◽  
2001 ◽  
Vol 158 (3) ◽  
pp. 1051-1060
Author(s):  
Claire Remacle ◽  
Denis Baurain ◽  
Pierre Cardol ◽  
René F Matagne
Keyword(s):  
Mitochondrial Genome ◽  
Chlamydomonas Reinhardtii ◽  
Complex I ◽  
Slow Growth ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Sequencing Analysis ◽  
Mitochondrial Complex ◽  
Genetical Analysis ◽  
Complex I Activity

Abstract The mitochondrial rotenone-sensitive NADH:ubiquinone oxidoreductase (complex I) comprises more than 30 subunits, the majority of which are encoded by the nucleus. In Chlamydomonas reinhardtii, only five components of complex I are coded for by mitochondrial genes. Three mutants deprived of complex I activity and displaying slow growth in the dark were isolated after mutagenic treatment with acriflavine. A genetical analysis demonstrated that two mutations (dum20 and dum25) affect the mitochondrial genome whereas the third mutation (dn26) is of nuclear origin. Recombinational analyses showed that dum20 and dum25 are closely linked on the genetic map of the mitochondrial genome and could affect the nd1 gene. A sequencing analysis confirmed this conclusion: dum20 is a deletion of one T at codon 243 of nd1; dum25 corresponds to a 6-bp deletion that eliminates two amino acids located in a very conserved hydrophilic segment of the protein.

scholarly journals Structure of inhibitor-bound mammalian complex I

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hannah R. Bridges ◽  
Justin G. Fedor ◽  
James N. Blaza ◽  
Andrea Di Luca ◽  
Alexander Jussupow ◽  
...  
Keyword(s):  
Complex I ◽  
Energy Coupling ◽  
Competitive Inhibitor ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Mouse Heart ◽  
Coupling Mechanism ◽  
Substrate Reduction ◽  
Mitochondrial Inner Membrane ◽  
Respiratory Complex I ◽  
Ubiquinone Binding

Abstract Respiratory complex I (NADH:ubiquinone oxidoreductase) captures the free energy from oxidising NADH and reducing ubiquinone to drive protons across the mitochondrial inner membrane and power oxidative phosphorylation. Recent cryo-EM analyses have produced near-complete models of the mammalian complex, but leave the molecular principles of its long-range energy coupling mechanism open to debate. Here, we describe the 3.0-Å resolution cryo-EM structure of complex I from mouse heart mitochondria with a substrate-like inhibitor, piericidin A, bound in the ubiquinone-binding active site. We combine our structural analyses with both functional and computational studies to demonstrate competitive inhibitor binding poses and provide evidence that two inhibitor molecules bind end-to-end in the long substrate binding channel. Our findings reveal information about the mechanisms of inhibition and substrate reduction that are central for understanding the principles of energy transduction in mammalian complex I.

scholarly journals Supramolecular Organization of the Respiratory Chain in Neurospora crassa Mitochondria

2007 ◽  
Vol 6 (12) ◽  
pp. 2391-2405 ◽  
Author(s):  
Isabel Marques ◽  
Norbert A. Dencher ◽  
Arnaldo Videira ◽  
Frank Krause
Keyword(s):  
Neurospora Crassa ◽  
Respiratory Chain ◽  
Complex I ◽  
Polyacrylamide Gel Electrophoresis ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Deletion Mutants ◽  
Supramolecular Organization ◽  
Wild Type ◽  
Respiratory Supercomplexes ◽  
Native Polyacrylamide Gel Electrophoresis

ABSTRACT The existence of specific respiratory supercomplexes in mitochondria of most organisms has gained much momentum. However, its functional significance is still poorly understood. The availability of many deletion mutants in complex I (NADH:ubiquinone oxidoreductase) of Neurospora crassa, distinctly affected in the assembly process, offers unique opportunities to analyze the biogenesis of respiratory supercomplexes. Herein, we describe the role of complex I in assembly of respiratory complexes and supercomplexes as suggested by blue and colorless native polyacrylamide gel electrophoresis and mass spectrometry analyses of mildly solubilized mitochondria from the wild type and eight deletion mutants. As an important refinement of the fungal respirasome model, we found that the standard respiratory chain of N. crassa comprises putative complex I dimers in addition to I-III-IV and III-IV supercomplexes. Three Neurospora mutants able to assemble a complete complex I, lacking only the disrupted subunit, have respiratory supercomplexes, in particular I-III-IV supercomplexes and complex I dimers, like the wild-type strain. Furthermore, we were able to detect the I-III-IV supercomplexes in the nuo51 mutant with no overall enzymatic activity, representing the first example of inactive respirasomes. In addition, III-IV supercomplexes were also present in strains lacking an assembled complex I, namely, in four membrane arm subunit mutants as well as in the peripheral arm nuo30.4 mutant. In membrane arm mutants, high-molecular-mass species of the 30.4-kDa peripheral arm subunit comigrating with III-IV supercomplexes and/or the prohibitin complex were detected. The data presented herein suggest that the biogenesis of complex I is linked with its assembly into supercomplexes.

scholarly journals Characterization of a subcomplex of mitochondrial NADH:ubiquinone oxidoreductase (complex I) lacking the flavoprotein part of the N-module

2007 ◽  
Vol 1767 (5) ◽  
pp. 393-400 ◽  
Author(s):  
Volker Zickermann ◽  
Klaus Zwicker ◽  
Maja A. Tocilescu ◽  
Stefan Kerscher ◽  
Ulrich Brandt
Keyword(s):  
Complex I ◽  
Nadh:Ubiquinone Oxidoreductase

scholarly journals Characterization of two novel redox groups in the respiratory NADH:ubiquinone oxidoreductase (complex I)

2000 ◽  
Vol 1459 (2-3) ◽  
pp. 305-309 ◽  
Author(s):  
Thorsten Friedrich ◽  
Benedikt Brors ◽  
Petra Hellwig ◽  
Lars Kintscher ◽  
Tim Rasmussen ◽  
...  
Keyword(s):  
Complex I ◽  
Nadh:Ubiquinone Oxidoreductase
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