Team:UC Davis/PhoR ChvI1

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that due to the amino acid similarity of ChvI to PhoB, ChvI is able to
that due to the amino acid similarity of ChvI to PhoB, ChvI is able to
act as a
act as a
-
phosphate regulatory in <i>E.coli</i>, as a PhoB substitute (3).</span><span
+
phosphate regulator in <i>E.coli</i> as a PhoB substitute (3).</span><span
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<span style="">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>Since
<span style="">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>Since
ChvI showed no abnormal activity
ChvI showed no abnormal activity
-
inside <i>Agrobacterium</i> <i>Tumefaciens</i> under phosphate
+
inside <i>Agrobacterium tumefaciens</i> under phosphate
limitation, it
limitation, it
-
cannot serve as the primary phosphate regulator in <i>Agrobacterium</i>
+
cannot serve as the primary phosphate regulator in <i>A. tumefaciens</i>
(3).<o:p></o:p></span></p>
(3).<o:p></o:p></span></p>
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</span><i>Note: ChvI was not required for phosphate regulation
</span><i>Note: ChvI was not required for phosphate regulation
-
in Agrobacterium Tumefaciens (3), but it might be involved in phosphate
+
in A. tumefaciens (3), but it might be involved in phosphate
-
regulation in Agrobacterium Tumefaciens in some way (3). Therefore, the
+
regulation in A. tumefaciens in some way (3). Therefore, the
possibility of crosstalk still exists</i><o:p></o:p></span></p>
possibility of crosstalk still exists</i><o:p></o:p></span></p>
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Note: Since
Note: Since
-
we are going to use Escherichia coli as our model chassis for this
+
we are going to use E. coli as our model chassis for this
project; we
project; we
had to make sure that our proteins will keep their characteristics of
had to make sure that our proteins will keep their characteristics of
our
our
-
interest after being placed inside the Escherichia coli.</span></i><span
+
interest after being placed inside the E. coli.</span></i><span
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<i>For example, VirG gene (promoter 1) after being introduced
<i>For example, VirG gene (promoter 1) after being introduced
-
into E.coli cells, started to behave as if it were a member of
+
into E. coli cells, started to behave as if it were a member of
phosphate
phosphate
regulon (note: PhoB function was necessary for virG induction by
regulon (note: PhoB function was necessary for virG induction by
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(3). It was not proven that ChvI activates other PhoB-dependent
(3). It was not proven that ChvI activates other PhoB-dependent
promoters or
promoters or
-
recognizes the same DNA sequence as PhoB (3).But, there has been
+
recognizes the same DNA sequence as PhoB (3). However, there has been
speculation
speculation
that since PhoR mediates PhoB phosphorylation and dephosphorylation, it
that since PhoR mediates PhoB phosphorylation and dephosphorylation, it
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Therefore, the best option would be to find a promoter
Therefore, the best option would be to find a promoter
-
from <i>Agrobacterium</i> that gets activated by ChvG/ChvI, a
+
from <i>A. tumefaciens</i> that gets activated by ChvG/ChvI, a
two-component
two-component
regulatory system only; and does not interact with any <i>E. coli</i>
regulatory system only; and does not interact with any <i>E. coli</i>

Latest revision as of 02:43, 22 October 2009

PhoR to ChvI

   

PhoR-->ChvI

           
It has been hypothesized that due to the amino acid similarity of ChvI to PhoB, ChvI is able to act as a phosphate regulator in E.coli as a PhoB substitute (3).

            Since ChvI showed no abnormal activity inside Agrobacterium tumefaciens under phosphate limitation, it cannot serve as the primary phosphate regulator in A. tumefaciens (3).

            Note: ChvI was not required for phosphate regulation in A. tumefaciens (3), but it might be involved in phosphate regulation in A. tumefaciens in some way (3). Therefore, the possibility of crosstalk still exists

      Due to the structural similarity of ChvI and PhoB, the possibility of crosstalk exists (3).

    Note: Since we are going to use E. coli as our model chassis for this project; we had to make sure that our proteins will keep their characteristics of our interest after being placed inside the E. coli. For example, VirG gene (promoter 1) after being introduced into E. coli cells, started to behave as if it were a member of phosphate regulon (note: PhoB function was necessary for virG induction by phosphate starvation)(6). Studies have suggested that the reason for this behavior was due to the fact that virG promoter 1 has two hexamer blocks which have the same positions as the pho genes (6).

            Studies have shown that ChvI probably activated Alkaline Phosphatase (AP) activity by activating transcription of PhoA (PhoA also gets activated by PhoB) (3). It was not proven that ChvI activates other PhoB-dependent promoters or recognizes the same DNA sequence as PhoB (3). However, there has been speculation that since PhoR mediates PhoB phosphorylation and dephosphorylation, it may do the same to ChvI(3).

            Therefore, the best option would be to find a promoter from A. tumefaciens that gets activated by ChvG/ChvI, a two-component regulatory system only; and does not interact with any E. coli system.