Acetate Activation in Methanosaeta thermophila : Characterization of the Key Enzymes Pyrophosphatase and Acetyl-CoA Synthetase
Joint Authors
Deppenmeier, Uwe
Welte, Cornelia
Berger, Stefanie
Source
Issue
Vol. 2012, Issue 2012 (31 Dec. 2012), pp.1-10, 10 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2012-08-15
Country of Publication
Egypt
No. of Pages
10
Main Subjects
Abstract EN
The thermophilic methanogen Methanosaeta thermophila uses acetate as sole substrate for methanogenesis.
It was proposed that the acetate activation reaction that is needed to feed acetate into the methanogenic pathway requires the hydrolysis of two ATP, whereas the acetate activation reaction in Methanosarcina sp.
is known to require only one ATP.
As these organisms live at the thermodynamic limit that sustains life, the acetate activation reaction in Mt.
thermophila seems too costly and was thus reevaluated.
It was found that of the putative acetate activation enzymes one gene encoding an AMP-forming acetyl-CoA synthetase was highly expressed.
The corresponding enzyme was purified and characterized in detail.
It catalyzed the ATP-dependent formation of acetyl-CoA, AMP, and pyrophosphate (PPi) and was only moderately inhibited by PPi.
The breakdown of PPi was performed by a soluble pyrophosphatase.
This enzyme was also purified and characterized.
The pyrophosphatase hydrolyzed the major part of PPi (KM=0.27±0.05 mM) that was produced in the acetate activation reaction.
Activity was not inhibited by nucleotides or PPi.
However, it cannot be excluded that other PPi-dependent enzymes take advantage of the remaining PPi and contribute to the energy balance of the cell.
American Psychological Association (APA)
Berger, Stefanie& Welte, Cornelia& Deppenmeier, Uwe. 2012. Acetate Activation in Methanosaeta thermophila : Characterization of the Key Enzymes Pyrophosphatase and Acetyl-CoA Synthetase. Archaea،Vol. 2012, no. 2012, pp.1-10.
https://search.emarefa.net/detail/BIM-462795
Modern Language Association (MLA)
Berger, Stefanie…[et al.]. Acetate Activation in Methanosaeta thermophila : Characterization of the Key Enzymes Pyrophosphatase and Acetyl-CoA Synthetase. Archaea No. 2012 (2012), pp.1-10.
https://search.emarefa.net/detail/BIM-462795
American Medical Association (AMA)
Berger, Stefanie& Welte, Cornelia& Deppenmeier, Uwe. Acetate Activation in Methanosaeta thermophila : Characterization of the Key Enzymes Pyrophosphatase and Acetyl-CoA Synthetase. Archaea. 2012. Vol. 2012, no. 2012, pp.1-10.
https://search.emarefa.net/detail/BIM-462795
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-462795