Sandbox Reserved 1051: Difference between revisions

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===Ag85C-E228Q===

The mutation introduced in Ag85C-E228Q causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C. 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 Ag85C-E228Q mutant. Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>

<Structure load='4QDZ' size='350' frame='true' align='right' caption='Ag85C-Hg' scene='Insert optional scene name here' />[[Image:Ag85C Hg.jpeg |100 xp|left|thumb|'''Figure 2. Mutated Ag85C enzyme with glutamate shift.''' 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 Ag85C-E228Q causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C. 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 Ag85C-E228Q mutant. Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>

Unlike other Ag85C mutants and modifications aforementioned, the Ag85C-E228Q 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 E228Q mutant provides additional support for the hypothesis that the natively kinked helix alpha-9 is central to the enzymatic function of Ag85C.<ref name="Favrot"/>

Sandbox Reserved 1051: Difference between revisions

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 ===Ag85C-E228Q===
-The mutation introduced in Ag85C-E228Q causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C. 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 Ag85C-E228Q mutant.  Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>
+<Structure load='4QDZ' size='350' frame='true' align='right' caption='Ag85C-Hg' scene='Insert optional scene name here' />[[Image:Ag85C Hg.jpeg |100 xp|left|thumb|'''Figure 2.  Mutated Ag85C enzyme with glutamate shift.''' 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 Ag85C-E228Q causes the Glu228 of the catalytic triad to be shifted 4 angstroms from its original position in the native structure of Ag85C. 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 Ag85C-E228Q mutant.  Overall, the enzyme functionality is decreased to only 17% activity.<ref name="Favrot"/>
 Unlike other Ag85C mutants and modifications aforementioned, the Ag85C-E228Q 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 E228Q mutant provides additional support for the hypothesis that the natively kinked helix alpha-9 is central to the enzymatic function of Ag85C.<ref name="Favrot"/>