Structural basis for the reversibility of proton pyrophosphatase

Regmi, Kamesh C.; Pizzio, Gastón A.; Gaxiola, Roberto A.

doi:10.1080/15592324.2016.1231294

Cited by 8 publications

(5 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This event, in turn, triggers the opening of the channel to the cytoplasmic interior and permits the PPi to exit; after which the proton is allowed to exit cytoplasmically along a salt bridge (consisting of charged and polar side chains acting as a proton wire) to stabilize the hydroxyl ion released on condensation to PPi (this sequence of events ensures that the completion of the driving process is made conditional on the completion of the driven one, as required to have the former 'drive' the latter). Finally, the resulting water molecule is then expelled into the cytoplasm and the salt bridge gate then closes as the enzyme is readied for the next run [91] (and see [92]). Although there appears to be no water involved in the structure of the channel, the proton is translocated via a variation of the Grotthuss mechanism involving the amino acid side chains [93,94].…”

Section: Disequilibria Conversion In the Alkaline Hydrothermal Vent Theory Of Abiogenesismentioning

confidence: 99%

On the beneficent thickness of water

Branscomb

Russell

2019

Interface Focus.

View full text Add to dashboard Cite

In the 1930s, Lars Onsager published his famous ‘reciprocal relations’ describing free energy conversion processes. Importantly, these relations were derived on the assumption that the fluxes of the processes involved in the conversion were proportional to the forces (free energy gradients) driving them. For chemical reactions, however, this condition holds only for systems operating close to equilibrium—indeed very close; nominally requiring driving forces to be smaller than k B T . Fairly soon thereafter, however, it was quite inexplicably observed that in at least some biological conversions both the reciprocal relations and linear flux–force dependency appeared to be obeyed no matter how far from equilibrium the system was being driven. No successful explanation of how this ‘paradoxical’ behaviour could occur has emerged and it has remained a mystery. We here argue, however, that this anomalous behaviour is simply a gift of water, of its viscosity in particular; a gift, moreover, without which life almost certainly could not have emerged. And a gift whose appreciation we primarily owe to recent work by Prof. R. Dean Astumian who, as providence has kindly seen to it, was led to the relevant insights by the later work of Onsager himself.

show abstract

Section: Disequilibria Conversion In the Alkaline Hydrothermal Vent Theory Of Abiogenesismentioning

confidence: 99%

On the beneficent thickness of water

Branscomb

Russell

2019

Interface Focus.

View full text Add to dashboard Cite

show abstract

“…This mechanism, named "binding change" (not to be confused with Boyer's "binding change" for F o F 1 -ATPase), does not ascribe any specific role to the proton released from the nucleophilic water molecule. Operation of this mechanism in reverse was proposed to explain PP i synthesis by plant mPPases (Regmi et al, 2016).…”

Section: Proposed Coupling Mechanisms Of H + -Transporting Mppase-promentioning

confidence: 99%

Energy Coupling in Cation-Pumping Pyrophosphatase—Back to Mitchell

Baykov

2020

Front. Plant Sci.

View full text Add to dashboard Cite

“…Under a favorable proton gradient, as is found in the phloem apoplasmic interface, a PM-localized type I H + -PPase (Long et al, 1995;Ratajczak et al, 1999;Langhans et al, 2001;Paez-Valencia et al, 2011;Regmi et al, 2015) has been proposed on thermodynamic (Davies et al, 1997) and structural grounds (Regmi et al, 2016), to function in reverse as a PPisynthase (Khadilkar et al, 2015;Pizzio et al, 2015). In fact, the bidirectionality of plant membrane-bound type I H + -PPases has been shown \y (Scholz-Starke et al, 2019) and suggested biochemically (Façanha and de Meis, 1998;Marsh et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Improved Yield and Photosynthate Partitioning in AVP1 Expressing Wheat (Triticum aestivum) Plants

et al. 2020

Self Cite

View full text Add to dashboard Cite

A fundamental factor to improve crop productivity involves the optimization of reduced carbon translocation from source to sink tissues. Here, we present data consistent with the positive effect that the expression of the Arabidopsis thaliana H +-PPase (AVP1) has on reduced carbon partitioning and yield increases in wheat. Immunohistochemical localization of H +-PPases (TaVP) in spring wheat Bobwhite L. revealed the presence of this conserved enzyme in wheat vasculature and sink tissues. Of note, immunogold imaging showed a plasma membrane localization of TaVP in sieve element-companion cell complexes of Bobwhite source leaves. These data together with the distribution patterns of a fluorescent tracer and [U 14 C]-sucrose are consistent with an apoplasmic phloem-loading model in wheat. Interestingly, 14 C-labeling experiments provided evidence for enhanced carbon partitioning between shoots and roots, and between flag leaves and milk stage kernels in AVP1 expressing Bobwhite lines. In keeping, there is a significant yield improvement triggered by the expression of AVP1 in these lines. Green house and field grown transgenic wheat expressing AVP1 also produced higher grain yield and number of seeds per plant, and exhibited an increase in root biomass when compared to null segregants. Another agriculturally desirable phenotype showed by AVP1 Bobwhite plants is a robust establishment of seedlings.

show abstract

Structural basis for the reversibility of proton pyrophosphatase

Cited by 8 publications

References 35 publications

On the beneficent thickness of water

On the beneficent thickness of water

Energy Coupling in Cation-Pumping Pyrophosphatase—Back to Mitchell

Improved Yield and Photosynthate Partitioning in AVP1 Expressing Wheat (Triticum aestivum) Plants

Contact Info

Product

Resources

About