scholarly journals Carbon and Nitrogen Sources Have No Impact on the Organization and Composition of Ustilago maydis Respiratory Supercomplexes

2021 ◽  
Vol 7 (1) ◽  
pp. 42
Author(s):  
Deyamira Matuz-Mares ◽  
Oscar Flores-Herrera ◽  
Guadalupe Guerra-Sánchez ◽  
Lucero Romero-Aguilar ◽  
Héctor Vázquez-Meza ◽  
...  

Respiratory supercomplexes are found in mitochondria of eukaryotic cells and some bacteria. A hypothetical role of these supercomplexes is electron channeling, which in principle should increase the respiratory chain efficiency and ATP synthesis. In addition to the four classic respiratory complexes and the ATP synthase, U. maydis mitochondria contain three type II NADH dehydrogenases (NADH for reduced nicotinamide adenine dinucleotide) and the alternative oxidase. Changes in the composition of the respiratory supercomplexes due to energy requirements have been reported in certain organisms. In this study, we addressed the organization of the mitochondrial respiratory complexes in U. maydis under diverse energy conditions. Supercomplexes were obtained by solubilization of U. maydis mitochondria with digitonin and separated by blue native polyacrylamide gel electrophoresis (BN-PAGE). The molecular mass of supercomplexes and their probable stoichiometries were 1200 kDa (I1:IV1), 1400 kDa (I1:III2), 1600 kDa (I1:III2:IV1), and 1800 kDa (I1:III2:IV2). Concerning the ATP synthase, approximately half of the protein is present as a dimer and half as a monomer. The distribution of respiratory supercomplexes was the same in all growth conditions. We did not find evidence for the association of complex II and the alternative NADH dehydrogenases with other respiratory complexes.

1991 ◽  
Vol 266 (1) ◽  
pp. 123-129
Author(s):  
D A Berkich ◽  
G D Williams ◽  
P T Masiakos ◽  
M B Smith ◽  
P D Boyer ◽  
...  
Keyword(s):  

2014 ◽  
Vol 34 (2) ◽  
Author(s):  
Asha Manikkoth Balakrishna ◽  
Holger Seelert ◽  
Sven-Hendric Marx ◽  
Norbert A. Dencher ◽  
Gerhard Grüber

In eukaryotic and prokaryotic cells, F-ATP synthases provide energy through the synthesis of ATP. The chloroplast F-ATP synthase (CF1FO-ATP synthase) of plants is integrated into the thylakoid membrane via its FO-domain subunits a, b, b’ and c. Subunit c with a stoichiometry of 14 and subunit a form the gate for H+-pumping, enabling the coupling of electrochemical energy with ATP synthesis in the F1 sector. Here we report the crystallization and structure determination of the c14-ring of subunit c of the CF1FO-ATP synthase from spinach chloroplasts. The crystals belonged to space group C2, with unit-cell parameters a=144.420, b=99.295, c=123.51 Å, and β=104.34° and diffracted to 4.5 Å resolution. Each c-ring contains 14 monomers in the asymmetric unit. The length of the c-ring is 60.32 Å, with an outer ring diameter 52.30 Å and an inner ring width of 40 Å.


2010 ◽  
Vol 1797 (11) ◽  
pp. 1828-1837 ◽  
Author(s):  
Kathrin Förster ◽  
Paola Turina ◽  
Friedel Drepper ◽  
Wolfgang Haehnel ◽  
Susanne Fischer ◽  
...  

2012 ◽  
Vol 496 ◽  
pp. 457-460
Author(s):  
Xiang Ping Kong

The growth conditions of a Geobacillus sp. were investigated by single-factor experiments. The strain was strictly aerobic bacterium, and could grow on hydrocarbons as the sole carbon source. The optimum carbon and nitrogen sources were 3.0% sucrose and 0.20% KNO3, respectively. The range of temperature, salinity and pH for the bacterial growth was 35-70 °C, 0-10% NaCl and 5.5-9.5, and good growth was obtained at 35-65 °C, 0.5-8% NaCl and 6.0-9.0, respectively. Particularly, the optimum temperature for the bacterial growth was between 50 °C and 60 °C. The strain had wide adaptability to the extreme conditions, and may be potentially applied to microbial enhanced oil recovery and oil-waste bioremediation technology.


2015 ◽  
Vol 290 (34) ◽  
pp. 21032-21041 ◽  
Author(s):  
Naman B. Shah ◽  
Thomas M. Duncan

F-type ATP synthases are rotary nanomotor enzymes involved in cellular energy metabolism in eukaryotes and eubacteria. The ATP synthase from Gram-positive and -negative model bacteria can be autoinhibited by the C-terminal domain of its ϵ subunit (ϵCTD), but the importance of ϵ inhibition in vivo is unclear. Functional rotation is thought to be blocked by insertion of the latter half of the ϵCTD into the central cavity of the catalytic complex (F1). In the inhibited state of the Escherichia coli enzyme, the final segment of ϵCTD is deeply buried but has few specific interactions with other subunits. This region of the ϵCTD is variable or absent in other bacteria that exhibit strong ϵ-inhibition in vitro. Here, genetically deleting the last five residues of the ϵCTD (ϵΔ5) caused a greater defect in respiratory growth than did the complete absence of the ϵCTD. Isolated membranes with ϵΔ5 generated proton-motive force by respiration as effectively as with wild-type ϵ but showed a nearly 3-fold decrease in ATP synthesis rate. In contrast, the ϵΔ5 truncation did not change the intrinsic rate of ATP hydrolysis with membranes. Further, the ϵΔ5 subunit retained high affinity for isolated F1 but reduced the maximal inhibition of F1-ATPase by ϵ from >90% to ∼20%. The results suggest that the ϵCTD has distinct regulatory interactions with F1 when rotary catalysis operates in opposite directions for the hydrolysis or synthesis of ATP.


2013 ◽  
Vol 74 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Irini Pateraki ◽  
Marta Renato ◽  
Joaquín Azcón-Bieto ◽  
Albert Boronat

2003 ◽  
Vol 185 (15) ◽  
pp. 4442-4449 ◽  
Author(s):  
Gregory M. Cook ◽  
Stefanie Keis ◽  
Hugh W. Morgan ◽  
Christoph von Ballmoos ◽  
Ulrich Matthey ◽  
...  

ABSTRACT We describe here purification and biochemical characterization of the F1Fo-ATP synthase from the thermoalkaliphilic organism Bacillus sp. strain TA2.A1. The purified enzyme produced the typical subunit pattern of an F1Fo-ATP synthase on a sodium dodecyl sulfate-polyacrylamide gel, with F1 subunits α, β, γ, δ, and ε and Fo subunits a, b, and c. The subunits were identified by N-terminal protein sequencing and mass spectroscopy. A notable feature of the ATP synthase from strain TA2.A1 was its specific blockage in ATP hydrolysis activity. ATPase activity was unmasked by using the detergent lauryldimethylamine oxide (LDAO), which activated ATP hydrolysis >15-fold. This activation was the same for either the F1Fo holoenzyme or the isolated F1 moiety, and therefore latent ATP hydrolysis activity is an intrinsic property of F1. After reconstitution into proteoliposomes, the enzyme catalyzed ATP synthesis driven by an artificially induced transmembrane electrical potential (Δψ). A transmembrane proton gradient or sodium ion gradient in the absence of Δψ was not sufficient to drive ATP synthesis. ATP synthesis was eliminated by the electrogenic protonophore carbonyl cyanide m-chlorophenylhydrazone, while the electroneutral Na+/H+ antiporter monensin had no effect. Neither ATP synthesis nor ATP hydrolysis was stimulated by Na+ ions, suggesting that protons are the coupling ions of the ATP synthase from strain TA2.A1, as documented previously for mesophilic alkaliphilic Bacillus species. The ATP synthase was specifically modified at its c subunits by N,N′-dicyclohexylcarbodiimide, and this modification inhibited ATP synthesis.


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