L-ATP is recognized by some cellular and viral enzymes: does chance drive enzymic enantioselectivity?
| Autor: | V. Boudou, Annalisa Verri, Silvio Spadari, Jean-Louis Imbach, Gilles Gosselin, Alessandra Montecucco, Federico Focher |
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| Rok vydání: | 1999 |
| Předmět: |
DNA Ligases
DNA Primase Thymidine Kinase Biochemistry chemistry.chemical_compound Adenosine Triphosphate RNA polymerase Deoxycytidine Kinase Escherichia coli Humans Simplexvirus Molecular Biology Polymerase chemistry.chemical_classification DNA ligase biology Stereoisomerism DNA DNA-Directed RNA Polymerases Cell Biology Molecular biology Adenosine Monophosphate Kinetics Enzyme chemistry Thymidine kinase biology.protein Nucleic acid Primase Research Article |
| Zdroj: | Biochemical Journal. 337:585-590 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj3370585 |
| Popis: | We demonstrate that l-ATP is recognized by some enzymes that are involved in the synthesis of nucleotides and nucleic acids. l-ATP, as well as its natural d-enantiomer, acts as a phosphate donor in the reaction catalysed by human deoxycytidine kinase, whereas it is not recognized by either enantioselective human thymidine kinase or non-enantioselective herpes virus thymidine kinase. l-ATP strongly inhibits (Ki 80 µM) the synthesis of RNA primers catalysed by DNA primase associated with human DNA polymerase α, whereas RNA synthesis catalysed by Escherichia coli RNA polymerase is completely unaffected. Moreover, l-ATP competitively inhibits ATP-dependent T4 DNA ligase (Ki 25 µM), suggesting that it interacts with the ATP-binding site of the enzyme. Kinetic studies demonstrated that l-ATP cannot be used as a cofactor in the ligase-catalysed joining reaction. On the other hand, l-AMP is used by T4 DNA ligase to catalyse the reverse reaction, even though a high level of intermediate circular nicked DNA molecules accumulates. Our results suggest that a lack of enantioselectivity of enzymes is more common than was believed a few years ago, and, given the absence of selective constraints against l-nucleosides in Nature, this may depend on chance more than on evolutionary strategy. |
| Databáze: | OpenAIRE |
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