Kinetics and Mechanism of Alkyl Transfer from Organocobalt(III) to Nickel(I):  Implications for the Synthesis of Acetyl Coenzyme A by CO Dehydrogenase

1997 ◽  
Vol 119 (7) ◽  
pp. 1648-1655 ◽  
Author(s):  
M. S. Ram ◽  
Glenn P. A. Yap ◽  
Louise Liable-Sands ◽  
Arnold L. Rheingold ◽  
Adam Marchaj ◽  
...  
Keyword(s):  
Coenzyme A ◽  
Kinetics And Mechanism ◽  
Co Dehydrogenase ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Alkyl Transfer

scholarly journals Operation of the CO Dehydrogenase/Acetyl Coenzyme A Pathway in both Acetate Oxidation and Acetate Formation by the Syntrophically Acetate-Oxidizing Bacterium Thermacetogenium phaeum

2005 ◽  
Vol 187 (10) ◽  
pp. 3471-3476 ◽  
Author(s):  
Satoshi Hattori ◽  
Alexander S. Galushko ◽  
Yoichi Kamagata ◽  
Bernhard Schink
Keyword(s):  
Gel Electrophoresis ◽  
Coenzyme A ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Acetate Oxidation ◽  
Co Dehydrogenase ◽  
Protein Patterns ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Cell Extracts

ABSTRACT Thermacetogenium phaeum is a homoacetogenic bacterium that can grow on various substrates, such as pyruvate, methanol, or H2/CO2. It can also grow on acetate if cocultured with the hydrogen-consuming methanogenic partner Methanothermobacter thermautotrophicus. Enzyme activities of the CO dehydrogenase/acetyl coenzyme A (CoA) pathway (CO dehydrogenase, formate dehydrogenase, formyl tetrahydrofolate synthase, methylene tetrahydrofolate dehydrogenase) were detected in cell extracts of pure cultures and of syntrophic cocultures. Mixed cell suspensions of T. phaeum and M. thermautotrophicus oxidized acetate rapidly and produced acetate after addition of H2/CO2 after a short time lag. CO dehydrogenase activity staining after native polyacrylamide gel electrophoresis exhibited three oxygen-labile bands which were identical in pure culture and coculture. Protein profiles of T. phaeum cells after sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the strain exhibited basically the same protein patterns in both pure and syntrophic culture. These results indicate that T. phaeum operates the CO dehydrogenase/acetyl-CoA pathway reversibly both in acetate oxidation and in reductive acetogenesis by using the same biochemical apparatus, although it has to couple this pathway to ATP synthesis in different ways.

scholarly journals Heterologous Expression of the Clostridium carboxidivorans CO Dehydrogenase Alone or Together with the Acetyl Coenzyme A Synthase Enables both Reduction of CO2 and Oxidation of CO by Clostridium acetobutylicum

2017 ◽  
Vol 83 (16) ◽  
Author(s):  
Ellinor D. Carlson ◽  
Eleftherios T. Papoutsakis
Keyword(s):  
Co Oxidation ◽  
Clostridium Acetobutylicum ◽  
Coenzyme A ◽  
Functional Expression ◽  
Co Dehydrogenase ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Content Type ◽  
Acetyl Coenzyme ◽  
Clostridium Carboxidivorans

ABSTRACT With recent advances in synthetic biology, CO2 could be utilized as a carbon feedstock by native or engineered organisms, assuming the availability of electrons. Two key enzymes used in autotrophic CO2 fixation are the CO dehydrogenase (CODH) and acetyl coenzyme A (acetyl-CoA) synthase (ACS), which form a bifunctional heterotetrameric complex. The CODH/ACS complex can reversibly catalyze CO2 to CO, effectively enabling a biological water-gas shift reaction at ambient temperatures and pressures. The CODH/ACS complex is part of the Wood-Ljungdahl pathway (WLP) used by acetogens to fix CO2, and it has been well characterized in native hosts. So far, only a few recombinant CODH/ACS complexes have been expressed in heterologous hosts, none of which demonstrated in vivo CO2 reduction. Here, functional expression of the Clostridium carboxidivorans CODH/ACS complex is demonstrated in the solventogen Clostridium acetobutylicum, which was engineered to express CODH alone or together with the ACS. Both strains exhibited CO2 reduction and CO oxidation activities. The CODH reactions were interrogated using isotopic labeling, thus verifying that CO was a direct product of CO2 reduction, and vice versa. CODH apparently uses a native C. acetobutylicum ferredoxin as an electron carrier for CO2 reduction. Heterologous CODH activity depended on actively growing cells and required the addition of nickel, which is inserted into CODH without the need to express the native Ni insertase protein. Increasing CO concentrations in the gas phase inhibited CODH activity and altered the metabolite profile of the CODH-expressing cells. This work provides the foundation for engineering a complete and functional WLP in nonnative host organisms. IMPORTANCE Functional expression of CO dehydrogenase (CODH) from Clostridium carboxidivorans was demonstrated in C. acetobutylicum, which is natively incapable of CO2 fixation. The expression of CODH, alone or together with the C. carboxidivorans acetyl-CoA synthase (ACS), enabled C. acetobutylicum to catalyze both CO2 reduction and CO oxidation. Importantly, CODH exhibited activity in both the presence and absence of ACS. 13C-tracer studies confirmed that the engineered C. acetobutylicum strains can reduce CO2 to CO and oxidize CO during growth on glucose.

Model Complexes for the NipSite of Acetyl Coenzyme A Synthase/Carbon Monoxide (CO) Dehydrogenase: Structure, Electrochemistry, and CO Reactivity

2018 ◽  
Vol 57 (21) ◽  
pp. 13713-13727 ◽  
Author(s):  
Anirban Bhandari ◽  
Ram Chandra Maji ◽  
Saikat Mishra ◽  
Akhilesh Kumar ◽  
Suman Kumar Barman ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Coenzyme A ◽  
Co Dehydrogenase ◽  
Model Complexes ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Acetyl Coenzyme A Synthase

scholarly journals A 5′ Leader Sequence Regulates Expression of Methanosarcinal CO Dehydrogenase/Acetyl Coenzyme A Synthase

2009 ◽  
Vol 191 (22) ◽  
pp. 7123-7128 ◽  
Author(s):  
Kimberly L. Anderson ◽  
Ethel E. Apolinario ◽  
Sheridan R. MacAuley ◽  
Kevin R. Sowers
Keyword(s):  
Transcription Initiation ◽  
Coenzyme A ◽  
Leader Sequence ◽  
Regulation Of Transcription ◽  
Co Dehydrogenase ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Acetyl Coenzyme A Synthase ◽  
Differential Transcription

ABSTRACT In vivo expression of CO dehydrogenase/acetyl coenzyme A synthase in Methanosarcina spp. is coordinately regulated in response to substrate by at least two mechanisms: differential transcription initiation and early elongation termination near the 3′ end of a 371-bp leader sequence. This is the first report of regulation of transcription elongation in the Archaea.

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