| Autor: |
Abdel Raheim, Salama R., McLennan, Alexander G. |
| Předmět: |
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| Zdroj: |
BMC Biochemistry; 2002, Vol. 3, p1-8, 8p, 1 Diagram, 2 Charts, 3 Graphs |
| Abstrakt: |
Background: The number of Nudix hydrolase family members varies widely among different organisms. In order to understand the reasons for the particular spectrum possessed by a given organism, the substrate specificity and function of different family members must be established. Results: The Y87G2A.14 Nudix hydrolase gene product of Caenorhabditis elegans has been expressed as a thioredoxin fusion protein in Escherichia coli and shown to be a CoA diphosphatase with catalytic activity towards CoA and its derivatives. The products of CoA hydrolysis were 3',5'- ADP and 4'-phosphopantetheine with Km and kcat values of 220 µM and 13.8 s-¹ respectively. CoA esters yielded 3',5'-ADP and the corresponding acyl-phosphopantetheine. Activity was optimal at pH 9.5 with 5 mM Mg2+ and fluoride was inhibitory with a Ki of 3 µM. The Y87G2A.14 gene product has a potential C-terminal tripeptide PTSI peroxisomal targeting signal - SKI. By fusing a Y87G2A.14 cDNA to the C-terminus of yeast-enhanced green fluorescent protein, the enzyme appeared to be targeted to peroxisomes by the SKI signal when transfected into yeast cells. Deletion of SKI abolished specific targeting. Conclusions: The presence of related sequences with potential PTSI or PTS2 peroxisomal targeting signals in other organisms suggests a conserved peroxisomal function for the CoA diphosphatase members of this group of Nudix hydrolases. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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