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A tridecameric c ring of the adenosine triphosphate (ATP) synthase from the thermoalkaliphilic Bacillus sp. strain TA2.A1 facilitates ATP synthesis at low electrochemical proton potential
- Source :
- Molecular Microbiology. 65:1181-1192
- Publication Year :
- 2007
- Publisher :
- Wiley, 2007.
-
Abstract
- Despite the thermodynamic problem imposed on alkaliphilic bacteria of synthesizing adenosine triphosphate (ATP) against a large inverted pH gradient and consequently a low electrochemical proton potential, these bacteria still utilize a proton-coupled F(1)F(o)-ATP synthase to synthesize ATP. One potential solution to this apparent thermodynamic problem would be the operation of a larger oligomeric c ring, which would raise the ion to ATP ratio, thus facilitating the conversion of a low electrochemical potential into a significant phosphorylation potential. To address this hypothesis, we have purified the oligomeric c ring from the thermoalkaliphilic bacterium Bacillus sp. strain TA2.A1 and determined the number of c-subunits using a novel mass spectrometry method, termed 'laser-induced liquid bead ion desorption' (LILBID). This technique allows the mass determination of non-covalently assembled, detergent-solubilized membrane protein complexes, and hence enables an accurate determination of c ring stoichiometries. We show that the Bacillus sp. strain TA2.A1 ATP synthase harbours a tridecameric c ring. The operation of a c ring with 13 subunits renders the thermodynamic problem of ATP synthesis at alkaline pH less severe and may represent a strategy for ATP synthesis at low electrochemical potential.
- Subjects :
- chemistry.chemical_classification
biology
ATP synthase
Strain (chemistry)
Chemiosmosis
Stereochemistry
Protein subunit
Proton-Motive Force
Bacillus
Microbiology
Protein Subunits
Proton-Translocating ATPases
chemistry.chemical_compound
Adenosine Triphosphate
Enzyme
Bacterial Proteins
chemistry
Biochemistry
biology.protein
Protons
Molecular Biology
Adenosine triphosphate
ATP synthase alpha/beta subunits
Electrochemical potential
Subjects
Details
- ISSN :
- 13652958 and 0950382X
- Volume :
- 65
- Database :
- OpenAIRE
- Journal :
- Molecular Microbiology
- Accession number :
- edsair.doi.dedup.....685a9bfe2873dee56bf11c4e9af584c2