| Autor: |
L, Wiesmüller, A A, Noegel, O, Bârzu, G, Gerisch, M, Schleicher |
| Rok vydání: |
1990 |
| Předmět: |
|
| Zdroj: |
The Journal of biological chemistry. 265(11) |
| ISSN: |
0021-9258 |
| Popis: |
A cDNA coding for UMP-CMP kinase from Dictyostelium discoideum was isolated from a lambda gt11 expression library and sequenced. The corresponding mRNA has a size of 0.7 kilobase and is down-regulated during early development of D. discoideum. Southern blotting demonstrated that the UMP-CMP kinase is encoded by a single gene. The deduced amino acid sequence of UMP-CMP kinase shows a high degree of homology with adenylate kinases from different sources with the highest degree of homology to cytosolic adenylate kinase from vertebrate muscle (43%). The enzyme expressed in Escherichia coli after cloning the cDNA into an ATG expression vector was purified and analyzed for its structural and kinetic properties. The UMP-CMP kinase uses preferentially ATP (Km,app = 25 microM) as phosphate donor and is specific for UMP (Km,app = 0.4 mM) and CMP (Km,app = 0.1 mM). The enzyme is strongly inhibited by the substrate analogue P1-(adenosine-5')-P5-(uridine-5')-pentaphosphate (Ki between 0.05 and 0.1 microM) and is inactivated by modification of free thiol groups with 5,5'-dithiobis(2-nitrobenzoic acid). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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