Autotrophic Carbon Dioxide Assimilation in Thermoproteales Revisited
- 1 July 2009
- journal article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 191 (13), 4286-4297
- https://doi.org/10.1128/jb.00145-09
Abstract
For Crenarchaea , two new autotrophic carbon fixation cycles were recently described. Sulfolobales use the 3-hydroxypropionate/4-hydroxybutyrate cycle, with acetyl-coenzyme A (CoA)/propionyl-CoA carboxylase as the carboxylating enzyme. Ignicoccus hospitalis ( Desulfurococcales ) uses the dicarboxylate/4-hydroxybutyrate cycle, with pyruvate synthase and phosphoenolpyruvate carboxylase being responsible for CO 2 fixation. In the two cycles, acetyl-CoA and two inorganic carbons are transformed to succinyl-CoA by different routes, whereas the regeneration of acetyl-CoA from succinyl-CoA proceeds via the same route. Thermoproteales would be an exception to this unifying concept, since for Thermoproteus neutrophilus , the reductive citric acid cycle was proposed as a carbon fixation mechanism. Here, evidence is presented for the operation of the dicarboxylate/4-hydroxybutyrate cycle in this archaeon. All required enzyme activities were detected in large amounts. The key enzymes of the cycle were strongly upregulated under autotrophic growth conditions, indicating their involvement in autotrophic CO 2 fixation. The corresponding genes were identified in the genome. 14 C-labeled 4-hydroxybutyrate was incorporated into the central building blocks in accordance with the key position of this compound in the cycle. Moreover, the results of previous 13 C-labeling studies, which could be reconciled with a reductive citric acid cycle only when some assumptions were made, were perfectly in line with the new proposal. We conclude that the dicarboxylate/4-hydroxybutyrate cycle is operating in CO 2 fixation in the strict anaerobic Thermoproteales as well as in Desulfurococcales .Keywords
This publication has 68 references indexed in Scilit:
- Transcriptional Map of Respiratory Versatility in the Hyperthermophilic Crenarchaeon Pyrobaculum aerophilumJournal of Bacteriology, 2009
- The Ribosomal Database Project: improved alignments and new tools for rRNA analysisNucleic Acids Research, 2008
- Structures and Functional Implications of an AMP-Binding Cystathionine β-Synthase Domain Protein from a Hyperthermophilic ArchaeonJournal of Molecular Biology, 2008
- A dicarboxylate/4-hydroxybutyrate autotrophic carbon assimilation cycle in the hyperthermophilic Archaeum Ignicoccus hospitalisProceedings of the National Academy of Sciences of the United States of America, 2008
- Synthesis of C 5 -dicarboxylic acids from C 2 -units involving crotonyl-CoA carboxylase/reductase: The ethylmalonyl-CoA pathwayProceedings of the National Academy of Sciences of the United States of America, 2007
- Insights into the Autotrophic CO 2 Fixation Pathway of the Archaeon Ignicoccus hospitalis : Comprehensive Analysis of the Central Carbon MetabolismJournal of Bacteriology, 2007
- Malonyl-Coenzyme A Reductase in the Modified 3-Hydroxypropionate Cycle for Autotrophic Carbon Fixation in Archaeal Metallosphaera and Sulfolobus sppJournal of Bacteriology, 2006
- Citric Acid Cycle in the Hyperthermophilic Archaeon Pyrobaculum islandicum Grown Autotrophically, Heterotrophically, and Mixotrophically with AcetateJournal of Bacteriology, 2006
- The origin and evolution of Archaea: a state of the artPhilosophical Transactions Of The Royal Society B-Biological Sciences, 2006
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976