Pyrophosphate-Dependent ATP Formation from Acetyl Coenzyme A in Syntrophus aciditrophicus, a New Twist on ATP Formation
Autor: | Jessica R. Sieber, Luke I. Szweda, Cody S. Sheik, Yongming Xie, Gregory B. Hurst, Elizabeth A. Karr, Housna Mouttaki, Robert P. Gunsalus, Lars Rohlin, Jonathan Erde, Michael J. McInerney, Hong Hanh Nguyen, Neil Q. Wofford, Kimberly L. James, Rachel R. Ogorzalek Loo, Luis A. Rios-Hernandez, Joseph A. Loo, Yanan Yang |
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Přispěvatelé: | Harwood, Caroline S |
Rok vydání: | 2016 |
Předmět: |
Deltaproteobacteria
0301 basic medicine Syntrophus aciditrophicus Proteome 030106 microbiology Acetates medicine.disease_cause 7. Clean energy Microbiology Pyrophosphate 03 medical and health sciences chemistry.chemical_compound Adenosine Triphosphate Affordable and Clean Energy Acetyl Coenzyme A Virology Coenzyme A Ligases Genetics medicine Phosphate acetyltransferase chemistry.chemical_classification Acetate kinase ATP synthase biology Gene Expression Profiling Metabolism Phosphate QR1-502 Diphosphates Infectious Diseases 030104 developmental biology Enzyme Biochemistry chemistry Metabolome biology.protein Biotechnology Research Article |
Zdroj: | mBio, Vol 7, Iss 4, p e01208-16 (2016) mBio, Vol 7, Iss 4 (2016) mBio mBio, vol 7, iss 4 |
ISSN: | 2150-7511 2161-2129 |
Popis: | Syntrophus aciditrophicus is a model syntrophic bacterium that degrades key intermediates in anaerobic decomposition, such as benzoate, cyclohexane-1-carboxylate, and certain fatty acids, to acetate when grown with hydrogen-/formate-consuming microorganisms. ATP formation coupled to acetate production is the main source for energy conservation by S. aciditrophicus. However, the absence of homologs for phosphate acetyltransferase and acetate kinase in the genome of S. aciditrophicus leaves it unclear as to how ATP is formed, as most fermentative bacteria rely on these two enzymes to synthesize ATP from acetyl coenzyme A (CoA) and phosphate. Here, we combine transcriptomic, proteomic, metabolite, and enzymatic approaches to show that S. aciditrophicus uses AMP-forming, acetyl-CoA synthetase (Acs1) for ATP synthesis from acetyl-CoA. acs1 mRNA and Acs1 were abundant in transcriptomes and proteomes, respectively, of S. aciditrophicus grown in pure culture and coculture. Cell extracts of S. aciditrophicus had low or undetectable acetate kinase and phosphate acetyltransferase activities but had high acetyl-CoA synthetase activity under all growth conditions tested. Both Acs1 purified from S. aciditrophicus and recombinantly produced Acs1 catalyzed ATP and acetate formation from acetyl-CoA, AMP, and pyrophosphate. High pyrophosphate levels and a high AMP-to-ATP ratio (5.9 ± 1.4) in S. aciditrophicus cells support the operation of Acs1 in the acetate-forming direction. Thus, S. aciditrophicus has a unique approach to conserve energy involving pyrophosphate, AMP, acetyl-CoA, and an AMP-forming, acetyl-CoA synthetase. IMPORTANCE Bacteria use two enzymes, phosphate acetyltransferase and acetate kinase, to make ATP from acetyl-CoA, while acetate-forming archaea use a single enzyme, an ADP-forming, acetyl-CoA synthetase, to synthesize ATP and acetate from acetyl-CoA. Syntrophus aciditrophicus apparently relies on a different approach to conserve energy during acetyl-CoA metabolism, as its genome does not have homologs to the genes for phosphate acetyltransferase and acetate kinase. Here, we show that S. aciditrophicus uses an alternative approach, an AMP-forming, acetyl-CoA synthetase, to make ATP from acetyl-CoA. AMP-forming, acetyl-CoA synthetases were previously thought to function only in the activation of acetate to acetyl-CoA. |
Databáze: | OpenAIRE |
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