Reverse Methionine Biosynthesis fromS-Adenosylmethionine in Eukaryotic Cells
| Autor: | Dominique Thomas, Aline Becker, Yolande Surdin-Kerjan |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
S-Adenosylmethionine
Saccharomyces cerevisiae Proteins Methyltransferase Homocysteine Molecular Sequence Data Vitamin U Homocysteine S-Methyltransferase 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase Biochemistry Fungal Proteins chemistry.chemical_compound Methionine Yeasts Amino Acid Sequence Methionine synthase Molecular Biology Gene Adaptor Proteins Signal Transducing chemistry.chemical_classification Thionucleosides Deoxyadenosines biology Membrane Proteins Cell Biology Cystathionine beta synthase Yeast Vitamin B 12 Enzyme Gene Expression Regulation chemistry biology.protein |
| Zdroj: | Journal of Biological Chemistry. 275:40718-40724 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m005967200 |
| Popis: | The intracellular ratio between methionine and its activated form S-adenosylmethionine (AdoMet) is of crucial importance for the one-carbon metabolism. AdoMet recycling into methionine was believed to be largely achieved through the methyl and the thiomethyladenosine cycles. We show here that in yeast, AdoMet recycling actually occurs mainly through the direct AdoMet-dependent remethylation of homocysteine. Compelling evidences supporting this result were obtained owing to the identification and functional characterization of two new genes, SAM4 and MHT1, that encode the yeast AdoMet-homocysteine methyltransferase and S-methylmethionine-homocysteine methyltransferase, respectively. Homologs of the Sam4 and Mht1 proteins exist in other eucaryotes, indicating that such enzymes would be universal and not restricted to the bacterial or fungal kingdoms. New pathways for AdoMet or S-methylmethionine-dependent methionine synthesis are presented. |
| Databáze: | OpenAIRE |
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