scholarly journals Application of the yeast Yarrowia lipolytica as a model to analyse human pathogenic mutations in mitochondrial complex I (NADH:ubiquinone oxidoreductase)

2004 ◽  
Vol 1659 (2-3) ◽  
pp. 197-205 ◽  
Author(s):  
Stefan Kerscher ◽  
Ljuban Grgic ◽  
Aurelio Garofano ◽  
Ulrich Brandt
2004 ◽  
Vol 1658 (1-2) ◽  
pp. 148-156 ◽  
Author(s):  
Albina Abdrakhmanova ◽  
Volker Zickermann ◽  
Mihnea Bostina ◽  
Michael Radermacher ◽  
Hermann Schägger ◽  
...  

2005 ◽  
Vol 33 (4) ◽  
pp. 840-844 ◽  
Author(s):  
U. Brandt ◽  
A. Abdrakhmanova ◽  
V. Zickermann ◽  
A. Galkin ◽  
S. Dröse ◽  
...  

The obligate aerobic yeast Yarrowia lipolytica has been established as a powerful model system for the analysis of mitochondrial complex I. Using a combination of genomic and proteomic approaches, a total of 37 subunits was identified. Several of the accessory subunits are predicted to be STMD (single transmembrane domain) proteins. Site-directed mutagenesis of Y. lipolytica complex I has provided strong evidence that a significant part of the ubiquinone reducing catalytic core resides in the 49 kDa and PSST subunits and can be modelled using X-ray structures of distantly related enzymes, i.e. water-soluble [NiFe] hydrogenases from Desulfovibrio spp. Iron–sulphur cluster N2, which is related to the hydrogenase proximal cluster, is directly involved in quinone reduction. Mutagenesis of His226 and Arg141 of the 49 kDa subunit provided detailed insight into the structure–function relationships around cluster N2. Overall, our findings suggest that proton pumping by complex I employs long-range conformational interactions and ubiquinone intermediates play a critical role in this mechanism.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Owen D. Jarman ◽  
Olivier Biner ◽  
John J. Wright ◽  
Judy Hirst

AbstractMitochondrial complex I (NADH:ubiquinone oxidoreductase) is a crucial metabolic enzyme that couples the free energy released from NADH oxidation and ubiquinone reduction to the translocation of four protons across the inner mitochondrial membrane, creating the proton motive force for ATP synthesis. The mechanism by which the energy is captured, and the mechanism and pathways of proton pumping, remain elusive despite recent advances in structural knowledge. Progress has been limited by a lack of model systems able to combine functional and structural analyses with targeted mutagenic interrogation throughout the entire complex. Here, we develop and present the α-proteobacterium Paracoccus denitrificans as a suitable bacterial model system for mitochondrial complex I. First, we develop a robust purification protocol to isolate highly active complex I by introducing a His6-tag on the Nqo5 subunit. Then, we optimize the reconstitution of the enzyme into liposomes, demonstrating its proton pumping activity. Finally, we develop a strain of P. denitrificans that is amenable to complex I mutagenesis and create a catalytically inactive variant of the enzyme. Our model provides new opportunities to disentangle the mechanism of complex I by combining mutagenesis in every subunit with established interrogative biophysical measurements on both the soluble and membrane bound enzymes.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Heddy Soufari ◽  
Camila Parrot ◽  
Lauriane Kuhn ◽  
Florent Waltz ◽  
Yaser Hashem

Abstract Mitochondria are the powerhouses of eukaryotic cells and the site of essential metabolic reactions. Complex I or NADH:ubiquinone oxidoreductase is the main entry site for electrons into the mitochondrial respiratory chain and constitutes the largest of the respiratory complexes. Its structure and composition vary across eukaryote species. However, high resolution structures are available only for one group of eukaryotes, opisthokonts. In plants, only biochemical studies were carried out, already hinting at the peculiar composition of complex I in the green lineage. Here, we report several cryo-electron microscopy structures of the plant mitochondrial complex I. We describe the structure and composition of the plant respiratory complex I, including the ancestral mitochondrial domain composed of the carbonic anhydrase. We show that the carbonic anhydrase is a heterotrimeric complex with only one conserved active site. This domain is crucial for the overall stability of complex I as well as a peculiar lipid complex composed of cardiolipin and phosphatidylinositols. Moreover, we also describe the structure of one of the plant-specific complex I assembly intermediates, lacking the whole PD module, in presence of the maturation factor GLDH. GLDH prevents the binding of the plant specific P1 protein, responsible for the linkage of the PP to the PD module.


Author(s):  
Heddy Soufari ◽  
Camila Parrot ◽  
Lauriane Kuhn ◽  
Florent Waltz ◽  
Yaser Hashem

AbstractMitochondria are the powerhouses of eukaryotic cells and the site of essential metabolic reactions. Their main purpose is to maintain the high ATP/ADP ratio that is required to fuel the countless biochemical reactions taking place in eukaryotic cells1. This high ATP/ADP ratio is maintained through oxidative phosphorylation (OXPHOS). Complex I or NADH:ubiquinone oxidoreductase is the main entry site for electrons into the mitochondrial respiratory chain and constitutes the largest of the respiratory complexes2. Its structure and composition varies across eukaryotes species. However, high resolution structures are available only for one group of eukaryotes, opisthokonts3–6. In plants, only biochemical studies were carried out, already hinting the peculiar composition of complex I in the green lineage. Here, we report several cryo-electron microscopy structures of the plant mitochondrial complex I at near-atomic resolution. We describe the structure and composition of the plant complex I including the plant-specific additional domain composed by carbonic anhydrase proteins. We show that the carbonic anhydrase is an heterotrimeric complex with only one conserved active site. This domain is crucial for the overall stability of complex I as well as a peculiar lipid complex composed cardiolipin and phosphatidylinositols. Moreover we also describe the structure of one of the plant-specific complex I assembly intermediate, lacking the whole PD module, in presence of the maturation factor GLDH. GLDH prevents the binding of the plant specific P1 protein, responsible for the linkage of the PP to the PD module. Finally, as the carbonic anhydrase domain is likely to be associated with complex I from numerous other known eukaryotes, we propose that our structure unveils an ancestral-like organization of mitochondrial complex I.


2004 ◽  
Vol 24 (19) ◽  
pp. 8447-8456 ◽  
Author(s):  
Guochang Huang ◽  
Hao Lu ◽  
Aijun Hao ◽  
Dominic C. H. Ng ◽  
Sathivel Ponniah ◽  
...  

ABSTRACT Mitochondria play essential roles in cellular energy production via the oxidative phosphorylation system (OXPHOS) consisting of five multiprotein complexes and also in the initiation of apoptosis. NADH:ubiquinone oxidoreductase (complex I) is the largest complex that catalyzes the first step of electron transfer in the OXPHOS system. GRIM-19 was originally identified as a nuclear protein with apoptotic nature in interferon (IFN)- and all-trans-retinoic acid (RA)-induced tumor cells. To reveal its biological role, we generated mice deficient in GRIM-19 by gene targeting. Homologous deletion of GRIM-19 causes embryonic lethality at embryonic day 9.5. GRIM-19−/− blastocysts show retarded growth in vitro and, strikingly, display abnormal mitochondrial structure, morphology, and cellular distribution. We reexamined the cellular localization of GRIM-19 in various cell types and found its primary localization in the mitochondria. Furthermore, GRIM-19 is detected in the native form of mitochondrial complex I. Finally, we show that elimination of GRIM-19 destroys the assembly and electron transfer activity of complex I and also influences the other complexes in the mitochondrial respiratory chain. Our result demonstrates that GRIM-19, a gene product with a specific role in IFN-RA-induced cell death, is a functional component of mitochondrial complex I and is essential for early embryonic development.


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