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ATP synthase alpha/beta subunits

 

 
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ATP synthase alpha/beta subunits
 
 
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ATPase
ATPase

ATPases are a class of enzymes that catalysis the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion....
s (or ATP synthase
ATP synthase

An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate from adenosine diphosphate and inorganic phosphate by using some form of energy....
s) are membrane-bound enzyme complexes/ion transporters that combine ATP
Adenosine triphosphate

This article is about the chemical used by cells as an energy carrier. For other uses, see ATP .Adenosine-5'-triphosphate is a multifunctional nucleotide, and plays an important role in cell biology as a coenzyme that is the "molecule unit of currency" of intracellular energy transfer....
 synthesis and/or hydrolysis with the transport of protons across a membrane. ATPases can harness the energy from a proton gradient, using the flux of ions across the membrane via the ATPase proton channel
Proton channel

Proton channels are ion channels for protons. Most prominent are the voltage-gated proton channels....
 to drive the synthesis of ATP.

Some ATPases work in reverse, using the energy from the hydrolysis of ATP to create a proton gradient.

There are different types of ATPases, which can differ in function (ATP synthesis and/or hydrolysis), structure (F-, V- and A-ATPases contain rotary motors) and in the type of ions they transport.



The alpha and beta (or A and B) subunits are found in the F1, V1, and A1 complexes of F-, V- and A-ATPases, respectively, as well as flagellar ATPase and the termination factor Rho.






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Encyclopedia




ATPase
ATPase

ATPases are a class of enzymes that catalysis the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion....
s (or ATP synthase
ATP synthase

An ATP synthase is a general term for an enzyme that can synthesize adenosine triphosphate from adenosine diphosphate and inorganic phosphate by using some form of energy....
s) are membrane-bound enzyme complexes/ion transporters that combine ATP
Adenosine triphosphate

This article is about the chemical used by cells as an energy carrier. For other uses, see ATP .Adenosine-5'-triphosphate is a multifunctional nucleotide, and plays an important role in cell biology as a coenzyme that is the "molecule unit of currency" of intracellular energy transfer....
 synthesis and/or hydrolysis with the transport of protons across a membrane. ATPases can harness the energy from a proton gradient, using the flux of ions across the membrane via the ATPase proton channel
Proton channel

Proton channels are ion channels for protons. Most prominent are the voltage-gated proton channels....
 to drive the synthesis of ATP.

Some ATPases work in reverse, using the energy from the hydrolysis of ATP to create a proton gradient.

There are different types of ATPases, which can differ in function (ATP synthesis and/or hydrolysis), structure (F-, V- and A-ATPases contain rotary motors) and in the type of ions they transport.

  • F-ATPase
    F-ATPase

    F-ATPase, also known as F-Type ATPase, is a transmembrane protein found in bacterial plasma membranes, mitochondrial inner membranes and in chloroplast thylakoid....
    s (F1F0-ATPases) in mitochondria, chloroplasts and bacterial plasma membranes are the prime producers of ATP, using the proton gradient generated by oxidative phosphorylation
    Oxidative phosphorylation

    Oxidative phosphorylation is a metabolic pathway that uses energy released by the redox of nutrients to produce adenosine triphosphate . Although the many forms of life on earth use a range of different nutrients, almost all carry out oxidative phosphorylation to produce ATP, the molecule that supplies energy to metabolism....
     (mitochondria) or photosynthesis
    Photosynthesis

    File:Seawifs global biosphere.jpgPhotosynthesis is a metabolic pathway that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight....
     (chloroplasts).
  • V-ATPase
    V-ATPase

    Vacuolar type H+-ATPase is a highly conserved evolutionarily ancient enzyme with remarkably diverse functions in Eukaryote organisms. V-ATPases acidifiy a wide array of intracellular organelles and proton pump across the Cell membrane of numerous cell types....
    s (V1V0-ATPases) are primarily found in eukaryotic vacuoles, catalysing ATP hydrolysis to transport solutes and lower pH in organelles.
  • A-ATPases (A1A0-ATPases) are found in Archaea and function like F-ATPases.
  • P-ATPases (E1E2-ATPases) are found in bacteria and in eukaryotic plasma membranes and organelles, and function to transport a variety of different ions across membranes.
  • E-ATPases are cell-surface enzymes that hydrolyse a range of nucleoside triphosphate
    Nucleoside triphosphate

    Nucleoside triphosphate is a nucleoside with three phosphates. Natural nucleoside triphosphates include adenosine triphosphate , guanosine triphosphate , cytidine triphosphate , thymidine triphosphate and uridine triphosphate ....
    s, including extracellular ATP.


The alpha and beta (or A and B) subunits are found in the F1, V1, and A1 complexes of F-, V- and A-ATPases, respectively, as well as flagellar ATPase and the termination factor Rho. The F-ATPases (or F1F0-ATPases), V-ATPases (or V1V0-ATPases) and A-ATPases (or A1A0-ATPases) are composed of two linked complexes: the F1, V1 or A1 complex contains the catalytic core that synthesizes/hydrolyses ATP, and the F0, V0 or A0 complex that forms the membrane-spanning pore. The F-, V- and A-ATPases all contain rotary motors, one that drives proton translocation across the membrane and one that drives ATP synthesis/hydrolysis.

In F-ATPases, there are three copies each of the alpha and beta subunits that form the catalytic core of the F1 complex, while the remaining F1 subunits (gamma, delta, epsilon) form part of the stalks. There is a substrate-binding site on each of the alpha and beta subunits, those on the beta subunits being catalytic, while those on the alpha subunits are regulatory. The alpha and beta subunits form a cylinder that is attached to the central stalk. The alpha/beta subunits undergo a sequence of conformational changes leading to the formation of ATP from ADP, which are induced by the rotation of the gamma subunit, itself is driven by the movement of protons through the F0 complex C subunit.

In V- and A-ATPases, the alpha/A and beta/B subunits of the V1 or A1 complex are homologous to the alpha and beta subunits in the F1 complex of F-ATPases, except that the alpha subunit is catalytic and the beta subunit is regulatory.

The alpha/A and beta/B subunits can each be divided into three regions, or domains, centred around the ATP-binding pocket, and based on structure and function. The central domain contains the nucleotide-binding residues that make direct contact with the ADP/ATP molecule.

Human proteins containing this domain

ATP5A1
ATP5A1

ATP synthase, H+ transporting, mitochondrial F1 complex, alpha subunit 1, cardiac muscle, also known as ATP5A1, is a human gene....
; ATP5B
ATP5B

ATP synthase, H+ transporting, mitochondrial F1 complex, beta polypeptide, also known as ATP5B, is a human gene....
; ATP6V1A
ATP6V1A

ATPase, H+ transporting, lysosomal 70kDa, V1 subunit A, also known as ATP6V1A, is a human gene.ReferencesFurther reading...
; ATP6V1B1
ATP6V1B1

ATPase, H+ transporting, lysosomal 56/58kDa, V1 subunit B1 , also known as ATP6V1B1, is a human gene....
; ATP6V1B2
ATP6V1B2

ATPase, H+ transporting, lysosomal 56/58kDa, V1 subunit B2, also known as ATP6V1B2, is a human gene....
;