2o1c: Difference between revisions

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==Overview==

The product of the Escherichia coli orf17 gene is a novel nucleoside, triphosphate pyrophosphohydrolase with a preference for dATP over the, other canonical (deoxy)nucleoside triphosphates, and it catalyzes the, hydrolysis of dATP through a nucleophilic attack at the beta-phosphorus to, produce dAMP and inorganic pyrophosphate. It has a pH optimum between 8.5, and 9.0, a divalent metal ion requirement with optimal activity at 5 mM, Mg2+, a Km of 0.8 mM and a kcat of 5.2 s-1 at 37 degrees C for dATP. dAMP, is a weak competitive inhibitor with a Ki of approximately 4 mM, while PPi, is a much stronger inhibitor with an apparent Ki of approximately 20, microM. The enzyme contains the highly conserved signature sequence, GXVEX2ETX6REVXEEX2I designating the MutT family of proteins. However, unlike the other nucleoside triphosphate pyrophosphohydrolases with this, conserved sequence, the Orf17 protein does not complement the mutT-, mutator phenotype, and thus must serve a different biological role in the, cell.

The product of the Escherichia coli orf17 gene is a novel nucleoside triphosphate pyrophosphohydrolase with a preference for dATP over the other canonical (deoxy)nucleoside triphosphates, and it catalyzes the hydrolysis of dATP through a nucleophilic attack at the beta-phosphorus to produce dAMP and inorganic pyrophosphate. It has a pH optimum between 8.5 and 9.0, a divalent metal ion requirement with optimal activity at 5 mM Mg2+, a Km of 0.8 mM and a kcat of 5.2 s-1 at 37 degrees C for dATP. dAMP is a weak competitive inhibitor with a Ki of approximately 4 mM, while PPi is a much stronger inhibitor with an apparent Ki of approximately 20 microM. The enzyme contains the highly conserved signature sequence GXVEX2ETX6REVXEEX2I designating the MutT family of proteins. However, unlike the other nucleoside triphosphate pyrophosphohydrolases with this conserved sequence, the Orf17 protein does not complement the mutT- mutator phenotype, and thus must serve a different biological role in the cell.

==About this Structure==

Line 13:

[[Category: Escherichia coli]]

[[Category: Single protein]]

[[Category: Amzel, L.M.]]

[[Category: Amzel, L M.]]

[[Category: Bianchet, M.A.]]

[[Category: Bianchet, M A.]]

[[Category: Gabelli, S.B.]]

[[Category: Gabelli, S B.]]

[[Category: PPV]]

[[Category: SO4]]

[[Category: nudix ntp hydrolase ntp pyrophosphohydrolase mutt dihydroneopterin triphosphate pyrophosphohydrolase folate biosynthesis]]

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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:13:18 2008''

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@@ Line 4: / Line 4: @@
 ==Overview==
-The product of the Escherichia coli orf17 gene is a novel nucleoside, triphosphate pyrophosphohydrolase with a preference for dATP over the, other canonical (deoxy)nucleoside triphosphates, and it catalyzes the, hydrolysis of dATP through a nucleophilic attack at the beta-phosphorus to, produce dAMP and inorganic pyrophosphate. It has a pH optimum between 8.5, and 9.0, a divalent metal ion requirement with optimal activity at 5 mM, Mg2+, a Km of 0.8 mM and a kcat of 5.2 s-1 at 37 degrees C for dATP. dAMP, is a weak competitive inhibitor with a Ki of approximately 4 mM, while PPi, is a much stronger inhibitor with an apparent Ki of approximately 20, microM. The enzyme contains the highly conserved signature sequence, GXVEX2ETX6REVXEEX2I designating the MutT family of proteins. However, unlike the other nucleoside triphosphate pyrophosphohydrolases with this, conserved sequence, the Orf17 protein does not complement the mutT-, mutator phenotype, and thus must serve a different biological role in the, cell.
+The product of the Escherichia coli orf17 gene is a novel nucleoside triphosphate pyrophosphohydrolase with a preference for dATP over the other canonical (deoxy)nucleoside triphosphates, and it catalyzes the hydrolysis of dATP through a nucleophilic attack at the beta-phosphorus to produce dAMP and inorganic pyrophosphate. It has a pH optimum between 8.5 and 9.0, a divalent metal ion requirement with optimal activity at 5 mM Mg2+, a Km of 0.8 mM and a kcat of 5.2 s-1 at 37 degrees C for dATP. dAMP is a weak competitive inhibitor with a Ki of approximately 4 mM, while PPi is a much stronger inhibitor with an apparent Ki of approximately 20 microM. The enzyme contains the highly conserved signature sequence GXVEX2ETX6REVXEEX2I designating the MutT family of proteins. However, unlike the other nucleoside triphosphate pyrophosphohydrolases with this conserved sequence, the Orf17 protein does not complement the mutT- mutator phenotype, and thus must serve a different biological role in the cell.
 ==About this Structure==
@@ Line 13: / Line 13: @@
 [[Category: Escherichia coli]]
 [[Category: Single protein]]
-[[Category: Amzel, L.M.]]
+[[Category: Amzel, L M.]]
-[[Category: Bianchet, M.A.]]
+[[Category: Bianchet, M A.]]
-[[Category: Gabelli, S.B.]]
+[[Category: Gabelli, S B.]]
 [[Category: PPV]]
 [[Category: SO4]]
 [[Category: nudix ntp hydrolase ntp pyrophosphohydrolase mutt dihydroneopterin triphosphate pyrophosphohydrolase folate biosynthesis]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 13:52:19 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:13:18 2008''