Skip to Main Content
Pyruvate ferredoxin oxidoreductase from the hyperthermophilic archaeon, Pyrococcus furious, functions as a CoA-dependent pyruvate decarboxylaseAuthor(s): Ma Kesen; A. Hutchins; Shi-Jean S. Sung; Michael W.W. Adams
Source: In: Proceedings of theNational Academy of Sciences USA. 94: 9608-9613.
Publication Series: Miscellaneous Publication
PDF: View PDF (298 KB)
DescriptionPyruvate ferredoxin oxidoreductase (POR) has been previously purified from the hyperthermophilic archaeon, Pyrococcus furiosus, an organism that grows optimally at 100°C by fermenting carbohydrates and peptides. The enzyme contains thiamine pyrophosphate and catalyzes the oxidative decarboxylation of pyruvate to acetyl-CoA and C02 and reduces P. furiosus ferredoxin. The authors show that this enzyme also catalyzes the formation of acetaldehyde from pyruvate in a CoA-dependent reaction. Desulfocoenzyme A substituted for CoA showing that the cofactor plays a structural rather than a catalytic role. Ferredoxin was not necessary for the pyruvate decarboxylase activity of POR, nor did it inhibit acetaldehyde production. The apparent Km values for CoA and pyruvate were 0.11 mM and 1.1 mM, respectively, and the optimal temperature for acetaldehyde formation was above 90°C. These data are comparable to those previously determined for the pyruvate oxidation reaction of POR. At 80°C (pH 8.0), the apparent Vm value for pyruvate decarboxylation was about 40 percent of the apparent Vm value for pyruvate oxidation rate (using P. furiosus ferredoxin as the electron acceptor). Tentative catalytic mechanisms for these two reactions are presented. In addition to POR, three other 2-keto acid ferredoxin oxidoreductases are involved in peptide fermentation by hyperthermophilic archaea. It is proposed that the various aldehydes produced by these oxidoreductases in vivo are used by two aldehyde-utilizing enzymes, alcohol dehydrogenase and aldehyde ferredoxin oxidoreductase, the physiological roles of which were previously unknown.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationKesen, Ma; Hutchins, A.; Sung, Shi-Jean S.; Adams, Michael W.W. 1997. Pyruvate ferredoxin oxidoreductase from the hyperthermophilic archaeon, Pyrococcus furious, functions as a CoA-dependent pyruvate decarboxylase. In: Proceedings of theNational Academy of Sciences USA. 94: 9608-9613.
- Heterologous production and characterization of two glyoxal oxidases from Pycnoporus cinnabarinus
- Selected soil enzyme activities in an oak-hickory forest following long-term prescribed burning
- Oxidative cleavage of diverse ethers by an extracellular fungal peroxygenase
XML: View XML