The monoheme cytochrome c subunit of Alternative Complex III is a direct electron donor to caa3 oxygen reductase in Rhodothermus marinus

2017 ◽  
Vol 398 (9) ◽  
pp. 1037-1044 ◽  
Author(s):  
Patrícia N. Refojo ◽  
Filipa Calisto ◽  
Miguel A. Ribeiro ◽  
Miguel Teixeira ◽  
Manuela M. Pereira
Keyword(s):  
Cytochrome C ◽  
Electron Donor ◽  
Complex Iii ◽  
Rhodothermus Marinus ◽  
Oxidoreductase Activity ◽  
C Subunit ◽  
Respiratory Chains ◽  
Oxygen Reductase ◽  
Alternative Complex Iii

Abstract Alternative Complex III (ACIII) is an example of the robustness and flexibility of prokaryotic respiratory chains. It performs quinol:cytochrome c oxidoreductase activity, being functionally equivalent to the bc1 complex but structurally unrelated. In this work we further explored ACIII investigating the role of its monoheme cytochrome c subunit (ActE). We expressed and characterized the individually isolated ActE, which allowed us to suggest that ActE is a lipoprotein and to show its function as a direct electron donor to the caa3 oxygen reductase.

scholarly journals Characterization and activity of Alternative Complex III from Rhodothermus marinus

2016 ◽  
Vol 1857 ◽  
pp. e36
Author(s):  
Filipa Calisto ◽  
Patrícia N. Refojo ◽  
Cláudia Bispo ◽  
Cláudia Andrade ◽  
Rui Gardner ◽  
...  
Keyword(s):  
Complex Iii ◽  
Rhodothermus Marinus ◽  
Alternative Complex Iii

scholarly journals Cryo-EM structure of the alternative complex III from Rhodothermus marinus

2018 ◽  
Vol 1859 ◽  
pp. e69
Author(s):  
Janet Vonck ◽  
Joana S. Sousa ◽  
Filipa Calisto ◽  
Deryck J. Mills ◽  
Julian D. Langer ◽  
...  
Keyword(s):  
Complex Iii ◽  
Rhodothermus Marinus ◽  
Alternative Complex Iii

scholarly journals The effects of lipid phase transitions on the interaction of mitochondrial NADH–ubiquinone oxidoreductase with ubiquinol–cytochrome c oxidoreductase

1979 ◽  
Vol 178 (2) ◽  
pp. 415-426 ◽  
Author(s):  
C Heron ◽  
M G Gore ◽  
C I Ragan
Keyword(s):  
Cytochrome C ◽  
Cytochrome B ◽  
Complex I ◽  
Complex Iii ◽  
Molar Ratio ◽  
Lipid Phase ◽  
Oxidoreductase Activity ◽  
Arrhenius Plots ◽  
Nadh Cytochrome ◽  
Ubiquinone 10

1. The endogenous phosphatidylcholine and phosphatidylethanolamine of Complexes I and III from bovine heart mitochondria may be completely replaced with 1,2-ditetradecanoyl-sn-glycero-3-phosphocholine with at least partial retention of activity. 2. The lipid-replaced enzymes associate in 1:1 molar ratio to give a Complex I–III unit catalysing NADH-cytochrome c oxidoreductase activity. 3. On increasing the concentration of ubiquinone-10 and the synthetic phospholipid, the lipid-replaced Complexes appear to operate independently of each other as in the natural membrane. Thus the lipid-replaced enzymes associate in exactly the same ways as the enzymes containing natural phospholipids. 4. Arrhenius plots of NADH–cytochrome c oxidoreductase activity reconstituted from lipid-replaced Complexes I and III exhibit changes in slope at 24 degrees C. When the concentrations of phospholipid and ubiquinone-10 are increased, the Arrhenius plots show discontinuities at 24 degrees C as well as changes in slope. 5. The kinetics of cytochrome b reduction by NADH were measured in mixtures containing 2 mol of Complex III/mol of Complex I. When the enzymes contained natural phospholipids. the reduction kinetics were biphasic. When the enzymes had been supplemented with further phospholipid and ubiquinone-10 the kinetics were monophasic. When lipid-replaced enzymes were supplemented with 1,2-ditetradecanoyl-sn-glycero-3-phosphocholine and ubiquinone-10, reduction of cytochrome b was monophasic above the phase-transition temperature of the lipid but biphasic below it. 6. These findings are interpreted in terms of the model for the interaction of Complexes in the natural membrane proposed by Heron, Ragan & Trum-power [(1978) Biochem. J. 174, 791–800].

scholarly journals The Monoheme c Subunit of Respiratory Alternative Complex III Is Not Essential for Electron Transfer to Cytochrome aa 3 in Flavobacterium johnsoniae

2021 ◽  
Author(s):  
Katarzyna Lorencik ◽  
Robert Ekiert ◽  
Yongtao Zhu ◽  
Mark J. McBride ◽  
Robert B. Gennis ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Energy Conversion ◽  
Protein Complexes ◽  
Complex Iii ◽  
Mitochondrial Complex ◽  
Unknown Mechanism ◽  
Flavobacterium Johnsoniae ◽  
Fundamental Process ◽  
C Subunit ◽  
Alternative Complex Iii

Energy conversion is a fundamental process of all organisms, realized by specialized protein complexes, one of which is alternative complex III (ACIII). ACIII is a functional analogue of well-known mitochondrial complex III, but operates according to a different, still unknown mechanism.

Structure of the Alternative Complex III from Flavobacterium johnsoniae in a Supercomplex with Cytochrome c Oxidase

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Robert Gennis ◽  
Chang Sun ◽  
Samir Benlekbir ◽  
Padmaja Venkatakrishnan ◽  
Yuhang Wang ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Complex Iii ◽  
Flavobacterium Johnsoniae ◽  
Alternative Complex Iii

scholarly journals The interaction between mitochondrial NADH-ubiquinone oxidoreductase and ubiquinol-cytochrome c oxidoreductase. Evidence for stoicheiometric association

1978 ◽  
Vol 174 (3) ◽  
pp. 783-790 ◽  
Author(s):  
C I Ragan ◽  
C Heron
Keyword(s):  
Cytochrome C ◽  
Complex I ◽  
Structural Features ◽  
Complex Iii ◽  
Molar Ratio ◽  
Oxidoreductase Activity ◽  
Ubiquinone Oxidoreductase ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Cytochrome C Reduction ◽  
Nadh Cytochrome

1. The NADH-ubiquinone oxidoreductase complex (Complex I) and the ubiquinol-cytochrome c oxidoreductase complex (Complex III) combine in a 1:1 molar ratio to give NADH-cytochrome c oxidoreductase (Complex I-Complex III). 2. Experiments on the inhibition of the NADH-cytochrome c oxidoreductase activity of mixtures of Complexes I and III by rotenone and antimycin indicate that electron transfer between a unit of Complex I-Complex III and extra molecules of Complexes I or III does not contribute to the overall rate of cytochrome c reduction. 3. The reduction by NADH of the cytochrome b of mixtures of Complexes I and III is biphasic. The extents of the fast and slow phases of reduction are determined by the proportion of the total Complex III specifically associated with Complex I. 4. Activation-energy measurements suggest that the structural features of the Complex I-Complex III unit promote oxidoreduction of endogenous ubiquinone-10.

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