D-galactose catabolism in archaea: operation of the DeLey–Doudoroff pathway in Haloferax volcanii
| Autor: | Peter Schönheit, Ulrike Johnsen, Andreas Reinhardt, Marius Ortjohann, Julia-Beate Tästensen |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Galactonate dehydratase
Fructose-bisphosphate aldolase ATP-binding cassette transporter Microbiology Genes Archaeal Gene Knockout Techniques 03 medical and health sciences chemistry.chemical_compound Genetics Haloferax volcanii Molecular Biology 030304 developmental biology 0303 health sciences biology 030306 microbiology Catabolism Chemistry Aldolase A Galactose biology.organism_classification Enzymes Biochemistry biology.protein Carbohydrate Metabolism Energy source Metabolic Networks and Pathways |
| Zdroj: | FEMS Microbiology Letters. 367 |
| ISSN: | 1574-6968 |
| Popis: | The haloarchaeon Haloferax volcanii was found to grow on D-galactose as carbon and energy source. Here we report a comprehensive analysis of D-galactose catabolism in H. volcanii. Genome analyses indicated a cluster of genes encoding putative enzymes of the DeLey–Doudoroff pathway for D-galactose degradation including galactose dehydrogenase, galactonate dehydratase, 2-keto-3-deoxygalactonate kinase and 2-keto-3-deoxy-6-phosphogalactonate (KDPGal) aldolase. The recombinant galactose dehydrogenase and galactonate dehydratase showed high specificity for D-galactose and galactonate, respectively, whereas KDPGal aldolase was promiscuous in utilizing KDPGal and also the C4 epimer 2-keto-3-deoxy-6-phosphogluconate as substrates. Growth studies with knock-out mutants indicated the functional involvement of galactose dehydrogenase, galactonate dehydratase and KDPGal aldolase in D-galactose degradation. Further, the transcriptional regulator GacR was identified, which was characterized as an activator of genes of the DeLey–Doudoroff pathway. Finally, genes were identified encoding components of an ABC transporter and a knock-out mutant of the substrate binding protein indicated the functional involvement of this transporter in D-galactose uptake. This is the first report of D-galactose degradation via the DeLey–Doudoroff pathway in the domain of archaea. |
| Databáze: | OpenAIRE |
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