ADP-ribosylation of glutamine synthetase in the cyanobacterium Synechocystis sp. strain PCC 6803
| Autor: | Nicholas H. Mann, Noel G. Carr, N J Silman |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
chemistry.chemical_classification
Adenosine Diphosphate Ribose Glutamine Glutamic Acid Glutamic acid Biology Chromatography Ion Exchange Cyanobacteria Microbiology Molecular biology Ammonium Chloride Enzyme Activation Enzyme activator Enzyme Biochemistry chemistry Species Specificity Glutamate-Ammonia Ligase Glutamine synthetase ADP-ribosylation Transferase NAD+ kinase Molecular Biology Research Article |
| Zdroj: | Journal of bacteriology. 177(12) |
| ISSN: | 0021-9193 |
| Popis: | Glutamine synthetase (GS) inactivation was observed in crude cell extracts and in the high-speed supernatant fraction from the cyanobacterium Synechocystis sp. strain PCC 6803 following the addition of ammonium ions, glutamine, or glutamate. Dialysis of the high-speed supernatant resulted in loss of inactivation activity, but this could be restored by the addition of NADH, NADPH, or NADP+ and, to a lesser extent, NAD+, suggesting that inactivation of GS involved ADP-ribosylation. This form of modification was confirmed both by labelling experiments using [32P]NAD+ and by chemical analysis of the hydrolyzed enzyme. Three different forms of GS, exhibiting no activity, biosynthetic activity only, or transferase activity only, could be resolved by chromatography, and the differences in activity were correlated with the extent of the modification. Both biosynthetic and transferase activities were restored to the completely inactive form of GS by treatment with phosphodiesterase. |
| Databáze: | OpenAIRE |
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