GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.
TableEdit
PMID:2394678
You don't have sufficient rights on this wiki to edit tables. Perhaps you need to log in. Changes you make in the Table editor will not be saved back to the wiki
See Help for Help on this wiki. See the documentation for how to use the table editor
| Citation |
Jin, SG, Prusti, RK, Roitsch, T, Ankenbauer, RG and Nester, EW (1990) Phosphorylation of the VirG protein of Agrobacterium tumefaciens by the autophosphorylated VirA protein: essential role in biological activity of VirG. J. Bacteriol. 172:4945-50 |
|---|---|
| Abstract |
Agrobacterium tumefaciens virulence genes are induced by plant signals through the VirA-VirG two-component regulatory system. The VirA protein is a membrane-spanning sensor molecule that possesses an autophosphorylating activity, and the VirG protein is a sequence-specific DNA-binding protein. In this report, we demonstrate that the VirG protein is phosphorylated by the VirA protein and that the phosphate is directly transferred from the phosphorylated VirA molecule (phosphohistidine) to the VirG protein. The chemical stability of the phospho-VirG bond suggested that the VirG protein was phosphorylated at the aspartate and/or glutamate residue. The phosphorylated VirG protein was reduced with tritiated sodium borohydride and subjected to proteolytic digestion with the Achromobacter protease I enzyme. The resulting peptide fragments were separated by C8 reversed-phase high-pressure liquid chromatography, and the tritium-labeled peptide was sequenced. Amino acid sequence data showed that the aspartate residue at position 52 was the only site phosphorylated. Changing this aspartate into asparagine resulted in a nonphosphorylatable and biologically nonfunctional gene product. As a control, a randomly chosen aspartate was changed into an asparagine (position 72), and no effect on its phosphorylation or biological activity was observed. Unlike its homologs, including CheA-CheY, EnvZ-OmpR, and NtrB-NtrC, the phospho-VirG molecule was very stable in vitro. The possible implications of these observations and the function of VirG phosphorylation in vir gene activation are discussed. |
| Links | |
| Keywords |
Aspartic Acid; Bacterial Proteins/isolation & purification; Bacterial Proteins/metabolism; Chromatography, High Pressure Liquid; DNA-Binding Proteins; Mutation; Phosphoproteins/isolation & purification; Phosphorylation; Plasmids; Rhizobium/genetics; Rhizobium/metabolism; Transcription Factors; Virulence Factors |
| public |
| Cancel |
