3-Hydroxypropionyl-Coenzyme A Dehydratase and Acryloyl-Coenzyme A Reductase, Enzymes of the Autotrophic 3-Hydroxypropionate/4-Hydroxybutyrate Cycle in the Sulfolobales
| Autor: | Johannes W. Kung, Robin Teufel, Birgit E. Alber, Georg Fuchs, Daniel Kockelkorn |
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| Rok vydání: | 2009 |
| Předmět: |
Archaeal Proteins
Coenzyme A Hydroxybutyrates Reductase Biology Models Biological Microbiology Genes Archaeal chemistry.chemical_compound Enoyl-CoA Hydratase Molecular Biology Sequence Homology Amino Acid Chloroflexus aurantiacus Enoyl-CoA hydratase biology.organism_classification Enzymes and Proteins chemistry Biochemistry Metallosphaera sedula Dehydratase Acyl Coenzyme A Propionates Oxidoreductases Sulfolobales Metabolic Networks and Pathways NADP Metallosphaera |
| Zdroj: | Journal of Bacteriology. 191:4572-4581 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.00068-09 |
| Popis: | A 3-hydroxypropionate/4-hydroxybutyrate cycle operates in autotrophic CO 2 fixation in various Crenarchaea , as studied in some detail in Metallosphaera sedula . This cycle and the autotrophic 3-hydroxypropionate cycle in Chloroflexus aurantiacus have in common the conversion of acetyl-coenzyme A (CoA) and two bicarbonates via 3-hydroxypropionate to succinyl-CoA. Both cycles require the reductive conversion of 3-hydroxypropionate to propionyl-CoA. In M. sedula the reaction sequence is catalyzed by three enzymes. The first enzyme, 3-hydroxypropionyl-CoA synthetase, catalyzes the CoA- and MgATP-dependent formation of 3-hydroxypropionyl-CoA. The next two enzymes were purified from M. sedula or Sulfolobus tokodaii and studied. 3-Hydroxypropionyl-CoA dehydratase, a member of the enoyl-CoA hydratase family, eliminates water from 3-hydroxypropionyl-CoA to form acryloyl-CoA. Acryloyl-CoA reductase, a member of the zinc-containing alcohol dehydrogenase family, reduces acryloyl-CoA with NADPH to propionyl-CoA. Genes highly similar to the Metallosphaera CoA synthetase, dehydratase, and reductase genes were found in autotrophic members of the Sulfolobales . The encoded enzymes are only distantly related to the respective three enzyme domains of propionyl-CoA synthase from C. aurantiacus , where this trifunctional enzyme catalyzes all three reactions. This indicates that the autotrophic carbon fixation cycles in Chloroflexus and in the Sulfolobales evolved independently and that different genes/enzymes have been recruited in the two lineages that catalyze the same kinds of reactions. |
| Databáze: | OpenAIRE |
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