Identification of the thiamin salvage enzyme thiazole kinase in Arabidopsis and maize
| Autor: | Rémi Zallot, Andrew D. Hanson, Meral Tunc-Ozdemir, Mohammad Yazdani, Valérie de Crécy-Lagard, David K. Shintani |
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| Rok vydání: | 2013 |
| Předmět: |
Mutant
Arabidopsis Plant Science Horticulture medicine.disease_cause Zea mays Biochemistry Gene Expression Regulation Enzymologic law.invention chemistry.chemical_compound Gene Expression Regulation Plant law Escherichia coli medicine Arabidopsis thaliana Thiamine Thiazole Molecular Biology Phylogeny Plant Proteins biology Arabidopsis Proteins Reverse Transcriptase Polymerase Chain Reaction Kinase Genetic Complementation Test Phosphotransferases food and beverages General Medicine biology.organism_classification Salvage enzyme Phosphotransferases (Alcohol Group Acceptor) Thiazoles chemistry Mutation Recombinant DNA |
| Zdroj: | Phytochemistry. 94:68-73 |
| ISSN: | 0031-9422 |
| Popis: | The breakdown of thiamin (vitamin B1) and its phosphates releases a thiazole moiety, 4-methyl-5-(2-hydroxyethyl)thiazole (THZ), that microorganisms and plants are able to salvage for re-use in thiamin synthesis. The salvage process starts with the ATP-dependent phosphorylation of THZ, which in bacteria is mediated by ThiM. The Arabidopsis and maize genomes encode homologs of ThiM (At3g24030 and GRMZM2G094558, respectively). Plasmid-driven expression of either plant homolog restored the ability of THZ to rescue Escherichia coli thiM deletant strains, showing that the plant proteins have ThiM activity in vivo. Enzymatic assays with purified recombinant proteins confirmed the presence of THZ kinase activity. Furthermore, ablating the Arabidopsis At3g24030 gene in a thiazole synthesis mutant severely impaired rescue by THZ. Collectively, these results show that ThiM homologs are the main source of THZ kinase activity in plants and are consequently crucial for thiamin salvage. |
| Databáze: | OpenAIRE |
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