Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.13.3 (
histidine kinase
)
2,405
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The plant pathogen Agrobacterium tumefaciens carries a virulence gene system that is required for the initiation of
crown gall
tumors on susceptible plants. Expression of the vir genes is activated by the VirA/VirG two component regulatory system. VirA is a
histidine kinase
which signals the presence of certain chemicals found at the site of a plant wound. The receiver domain located at its carboxyl terminus defines VirA as a hybrid
histidine kinase
. Here, we show that the VirA receiver interacts with the DNA-binding domain of VirG. This finding supports the hypothesis that the receiver acts as a recruiting factor for VirG. In addition, we show that removal of the VirA receiver allowed vir gene expression in response to glucose in a dose dependent manner, indicating that the receiver controls VirG activation and suggesting that the supplementary ChvE-sugar signal increases this activity.
...
PMID:The Receiver of the Agrobacterium tumefaciens VirA Histidine Kinase Forms a Stable Interaction with VirG to Activate Virulence Gene Expression. 2677 77
Agrobacterium tumefaciens is the agent that causes
crown gall
tumor disease on more than 140 species of dicotyledonous plants. Chemotaxis of A. tumefaciens toward the wound sites of the host plant is the first step to recognize the host. CheW is a coupling protein that bridges the
histidine kinase
CheA and the chemoreceptors to form the chemotaxis core signaling complex and plays a crucial role in the assembly and function of the large chemosensory array. Unlike all previously reported chemotaxis systems, A. tumefaciens has only one major che operon but two cheW homologs (atu2075 as cheW
1
and atu2617 as cheW
2
) on unlinked loci. The in-frame deletion of either cheW gene significantly affects A. tumefaciens chemotaxis but does not abolish the chemotaxis, unless both cheW genes were deleted. The effect of cheW
2
deletion on the chemotaxis is more severe than that of cheW
1
deletion. Either CheW can interact with CheA and couple it to the cell poles. The promoter activity of cheW
2
is always higher than that of cheW
1
under all of the tested conditions. When two cheW genes were adjusted to the same expression level by using the identical promoter, the difference between the effects of two CheW proteins on the chemotaxis still existed. Therefore, we envision that both the different molecular ratio of two CheW proteins in cell and the different affinities of two CheW proteins with CheA and chemoreceptors result in the efficiency difference of two CheW proteins in functioning in the large chemosensory array.
...
PMID:Two Agrobacterium tumefaciens CheW Proteins Are Incorporated into One Chemosensory Pathway with Different Efficiencies. 2918 66
