scholarly journals Structural basis of redox modulation on chloroplast ATP synthase

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Jay-How Yang ◽  
Dewight Williams ◽  
Eaazhisai Kandiah ◽  
Petra Fromme ◽  
Po-Lin Chiu
Keyword(s):  
Atp Synthase ◽  
Higher Plants ◽  
Atp Synthesis ◽  
Smooth Transition ◽  
Structural Basis ◽  
Energy Regulation ◽  
Redox Modulation ◽  
Disulfide Linkage ◽  
Chloroplast Atp Synthase ◽  
Γ Subunit

AbstractIn higher plants, chloroplast ATP synthase has a unique redox switch on its γ subunit that modulates enzyme activity to limit ATP hydrolysis at night. To understand the molecular details of the redox modulation, we used single-particle cryo-EM to determine the structures of spinach chloroplast ATP synthase in both reduced and oxidized states. The disulfide linkage of the oxidized γ subunit introduces a torsional constraint to stabilize the two β hairpin structures. Once reduced, free cysteines alleviate this constraint, resulting in a concerted motion of the enzyme complex and a smooth transition between rotary states to facilitate the ATP synthesis. We added an uncompetitive inhibitor, tentoxin, in the reduced sample to limit the flexibility of the enzyme and obtained high-resolution details. Our cryo-EM structures provide mechanistic insight into the redox modulation of the energy regulation activity of chloroplast ATP synthase.

C-Terminal Mutations in the Chloroplast ATP Synthase γ Subunit Impair ATP Synthesis and Stimulate ATP Hydrolysis†

Biochemistry ◽  
2008 ◽  
Vol 47 (2) ◽  
pp. 836-844 ◽  
Author(s):  
Feng He ◽  
Hardeep S. Samra ◽  
Eric A. Johnson ◽  
Nicholas R. Degner ◽  
Richard E. McCarty ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Chloroplast Atp Synthase ◽  
Γ Subunit

scholarly journals ECS-based investigation of chloroplast ATP synthase regulation

2020 ◽  
Author(s):  
Felix Buchert ◽  
Benjamin Bailleul ◽  
Pierre Joliot
Keyword(s):  
Atp Synthase ◽  
Redox Regulation ◽  
Spectroscopic Method ◽  
Atp Synthesis ◽  
Redox States ◽  
Chloroplast Atp Synthase ◽  
Γ Subunit ◽  
Synthase Regulation

AbstractThe chloroplast ATP synthase (CF1Fo) contains a specific feature to the green lineage: a γ-subunit redox domain which contains a cysteine couple and interacts with the torque-generating βDELSEED-loop. Based on the recently solved structure of this domain, it was proposed to function as a chock. In vitro, γ-disulfide formation slows down the activity of the CF1Fo at low transmembrane electrochemical proton gradient . Here, we utilize in vivo absorption spectroscopy measurements for functional CF1Fo activity characterization in Arabidopsis leaves. The spectroscopic method allows us to measure the present in dark-adapted leaves, and to identify its mitochondrial sources. Furthermore, we follow the fate of the extra generated by an illumination, including its osmotic and electric components, and from there we estimate the lifetime of the light-generated ATP. In contrast with a previous report [Joliot and Joliot, Biochim. Biophys. Acta, 1777 (2008) 676-683], the CF1Fo γ-subunit exists mostly in an oxidized form in the dark-adapted state. To study the redox regulation of the CF1Fo, we used thiol agent infiltration in WT and a mutant that does not form the γ-disulfide. The obtained -dependent CF1Fo activity profile in the two γ-redox states in vivo reconciles with previous biochemical in vitro findings [Junesch and Gräber, Biochim. Biophys. Acta, 893 (1987) 275-288]. The highest rates of ATP synthesis we measured in the two γ-redox state were similar at high . In the presence of the γ-dithiol, similar rates were obtained at a ~45 mV lower value compared to the oxidized state, which closely resembled the energetic gap of 0.7 ΔpH units reported in vitro.

scholarly journals Two genes, atpC1 and atpC2, for the γ subunit of Arabidopsis thaliana chloroplast ATP synthase

1991 ◽  
Vol 266 (12) ◽  
pp. 7333-7338
Author(s):  
N Inohara ◽  
A Iwamoto ◽  
Y Moriyama ◽  
S Shimomura ◽  
M Maeda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Atp Synthase ◽  
Chloroplast Atp Synthase ◽  
Γ Subunit

scholarly journals An ATP synthase harboring an atypical γ-subunit is involved in ATP synthesis in tomato fruit chromoplasts

2013 ◽  
Vol 74 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Irini Pateraki ◽  
Marta Renato ◽  
Joaquín Azcón-Bieto ◽  
Albert Boronat
Keyword(s):  
Atp Synthase ◽  
Tomato Fruit ◽  
Atp Synthesis ◽  
Γ Subunit

Kinetics of Proton-Transport-Coupled ATP Synthesis Catalyzed by the Chloroplast ATP Synthase

1986 ◽  
Vol 90 (11) ◽  
pp. 1034-1040 ◽  
Author(s):  
P. Gräber ◽  
P. Fromme ◽  
U. Junesch ◽  
G. Schmidt ◽  
G. Thulke
Keyword(s):  
Atp Synthase ◽  
Proton Transport ◽  
Atp Synthesis ◽  
Chloroplast Atp Synthase ◽  
Kinetics Of

The C-Terminal Domain of the ε Subunit of the Chloroplast ATP Synthase Is Not Required for ATP Synthesis†

Biochemistry ◽  
2002 ◽  
Vol 41 (51) ◽  
pp. 15130-15134 ◽  
Author(s):  
Kristine F. Nowak ◽  
Vazha Tabidze ◽  
Richard E. McCarty
Keyword(s):  
Atp Synthase ◽  
Atp Synthesis ◽  
Chloroplast Atp Synthase ◽  
Terminal Domain

scholarly journals Feedback limitation of photosynthesis at high CO2 acts by modulating the activity of the chloroplast ATP synthase

2009 ◽  
Vol 36 (11) ◽  
pp. 893 ◽  
Author(s):  
Olavi Kiirats ◽  
Jeffrey A. Cruz ◽  
Gerald E. Edwards ◽  
David M. Kramer
Keyword(s):  
Electron Transfer ◽  
Atp Synthase ◽  
Atp Synthesis ◽  
Nicotiana Sylvestris ◽  
O2 Evolution ◽  
High Co2 ◽  
Chloroplast Atp Synthase ◽  
Low Co2 ◽  
Photosynthetic Electron Transfer

It was previously shown that photosynthetic electron transfer is controlled under low CO2 via regulation of the chloroplast ATP synthase. In the current work, we studied the regulation of photosynthesis under feedback limiting conditions, where photosynthesis is limited by the capacity to utilise triose-phosphate for synthesis of end products (starch or sucrose), in a starch-deficient mutant of Nicotiana sylvestris Speg. & Comes. At high CO2, we observed feedback control that was progressively reversed by increasing O2 levels from 2 to 40%. The activity of the ATP synthase, probed in vivo by the dark-interval relaxation kinetics of the electrochromic shift, was proportional to the O2-induced increases in O2 evolution from PSII (JO2), as well as the sum of Rubisco oxygenation (vo) and carboxylation (vc) rates. The altered ATP synthase activity led to changes in the light-driven proton motive force, resulting in regulation of the rate of plastoquinol oxidation at the cytochrome b6f complex, quantitatively accounting for the observed control of photosynthetic electron transfer. The ATP content of the cell decreases under feedback limitation, suggesting that the ATP synthesis was downregulated to a larger extent than ATP consumption. This likely resulted in slowing of ribulose bisphosphate regeneration and JO2). Overall, our results indicate that, just as at low CO2, feedback limitations control the light reactions of photosynthesis via regulation of the ATP synthase, and can be reconciled with regulation via stromal Pi, or an unknown allosteric affector.

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