Sandbox Reserved 1051: Difference between revisions

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[[Image:E228Q zoom.png |100 xp|left|thumb|'''Figure 9.''' [http://proteopedia.org/wiki/index.php/4qdz Ag85C-E228Q] active site. The glutamate residue is shifted four angstroms in the mutated form of this enzyme causing a rearrangement of hydrogen bonds within the enzyme. The histidine residue, labeled in pink, takes on two conformations, binding with alternative serine residues, labeled in red.]]

The mutation introduced in [http://proteopedia.org/wiki/index.php/4qdz Ag85C-E228Q] (Figure 8) causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C (Figure 9). Due to the shift of Glu228 is the loss of hydrogen bonds between Ser124 and His260. Instead, His260 ~~hydrogen~~ bonds with Ser148, which also results from the shift of Glu228. A weak electron density difference in the His260 position of the native and mutated structures was also noted, suggesting that the residue may take on two alternative conformations in the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene> mutant. Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>

The mutation introduced in [http://proteopedia.org/wiki/index.php/4qdz Ag85C-E228Q] (Figure 8) causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C (Figure 9). Due to the shift of Glu228 is the loss of hydrogen bonds between Ser124 and His260. Instead, <scene name='69/694218/4qdz/1'>His260 bonds with Ser148</scene>, which also results from the shift of Glu228. A weak electron density difference in the His260 position of the native and mutated structures was also noted, suggesting that the residue may take on two alternative conformations in the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene> mutant. Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>

Unlike other Ag85C mutants and modifications aforementioned, the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene>does not eliminate any hydrogen bonds in the catalytic triad. Rather, it simply replaces a carboxylate moiety with an amide. Further, the structural change observed in the low-energy conformation of the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene> mutant provides additional support for the hypothesis that the natively kinked helix α-9 is central to the enzymatic function of Ag85C.<ref name="Favrot"/>

Sandbox Reserved 1051: Difference between revisions

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@@ Line 56: / Line 56: @@
 [[Image:E228Q zoom.png |100 xp|left|thumb|'''Figure 9.''' [http://proteopedia.org/wiki/index.php/4qdz Ag85C-E228Q] active site.  The glutamate residue is shifted four angstroms in the mutated form of this enzyme causing a rearrangement of hydrogen bonds within the enzyme. The histidine residue, labeled in pink, takes on two conformations, binding with alternative serine residues, labeled in red.]]
-The mutation introduced in [http://proteopedia.org/wiki/index.php/4qdz Ag85C-E228Q] (Figure 8) causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C (Figure 9). Due to the shift of Glu228 is the loss of hydrogen bonds between Ser124 and His260.  Instead, His260 hydrogen bonds with Ser148, which also results from the shift of Glu228.  A weak electron density difference in the His260 position of the native and mutated structures was also noted, suggesting that the residue may take on two alternative conformations in the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene> mutant.  Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>
+The mutation introduced in [http://proteopedia.org/wiki/index.php/4qdz Ag85C-E228Q] (Figure 8) causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C (Figure 9). Due to the shift of Glu228 is the loss of hydrogen bonds between Ser124 and His260.  Instead, <scene name='69/694218/4qdz/1'>His260 bonds with Ser148</scene>, which also results from the shift of Glu228.  A weak electron density difference in the His260 position of the native and mutated structures was also noted, suggesting that the residue may take on two alternative conformations in the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene> mutant.  Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>
 Unlike other Ag85C mutants and modifications aforementioned, the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene>does not eliminate any hydrogen bonds in the catalytic triad.  Rather, it simply replaces a carboxylate moiety with an amide.  Further, the structural change observed in the low-energy conformation of the <scene name='69/694218/Ag85c-e228q/1'>Ag85C-E228Q</scene> mutant provides additional support for the hypothesis that the natively kinked helix α-9 is central to the enzymatic function of Ag85C.<ref name="Favrot"/>