Phosphoglycerate Kinase: Difference between revisions

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The general mechanism is a single displacement Sn2 reaction in which the ADP-B-phosphate oxygen atom initiates nucleophilic attack on the 1-phosphate group of 1-3biphosphoglycerate. Thus, the phosphoryl group is transferred directly via a charged transition state. The product, ATP, is favored because it's negatively charged oxygens of the 3 phosphates form <scene name='Shane_Harmon_Sandbox/Atp/5'>hydrogen bonds</scene> with the enzyme. The 3 hydrogen bonds of ATP are favored over the 2 hydrogen bonds of ADP.

The general mechanism is a single displacement Sn2 reaction in which the ADP-B-phosphate oxygen atom initiates nucleophilic attack on the 1-phosphate group of 1-3biphosphoglycerate <ref> Auerbach, Gunter et al. 1997. Closed Structure of phosphoglycerate kinase from Thermotoga maritima reveals the catalytic mechanism and determinants of thermal stability. Structure. 5:1475-1483.</ref>. Thus, the phosphoryl group is transferred directly via a charged transition state. The product, ATP, is favored because it's negatively charged oxygens of the 3 phosphates form <scene name='Shane_Harmon_Sandbox/Atp/5'>hydrogen bonds</scene> with the enzyme. The 3 hydrogen bonds of ATP are favored over the 2 hydrogen bonds of ADP.

[[Image:PGKmechanism2.jpg]]

Two specific residues known to be necessary for catalysis are <scene name='Shane_Harmon_Sandbox/197_and_38/2'>Lys 197 and Arg 36</scene>. Lys 197 secures 1,3-biphosphoblycerate in the closed conformation, and it has been proposed that the transition state intermediary is stabilized by the highly conserved Lys 197 as it transfers the phosphate group. Additionally, it has been shown that Arg 38 is also necessary for catalytic function. Arg 36 has been shown to stabilize a water molecule in the closed conformation and may form a hydrogen bond with the ATP product.

Two specific residues known to be necessary for catalysis are <scene name='Shane_Harmon_Sandbox/197_and_38/2'>Lys 197 and Arg 36</scene>. Lys 197 secures 1,3-biphosphoblycerate in the closed conformation, and it has been proposed that the transition state intermediary is stabilized by the highly conserved Lys 197 as it transfers the phosphate group. Additionally, it has been shown that Arg 38 is also necessary for catalytic function. Arg 36 has been shown to stabilize a water molecule in the closed conformation and may form a hydrogen bond with the ATP product <ref> Auerbach, Gunter et al. 1997. Closed Structure of phosphoglycerate kinase from Thermotoga maritima reveals the catalytic mechanism and determinants of thermal stability. Structure. 5:1475-1483.</ref>.

Phosphoglycerate Kinase: Difference between revisions

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-The general mechanism is a single displacement Sn2 reaction in which the ADP-B-phosphate oxygen atom initiates nucleophilic attack on the 1-phosphate group of 1-3biphosphoglycerate.  Thus, the phosphoryl group is transferred directly via a charged transition state.  The product, ATP, is favored because it's negatively charged oxygens of the 3 phosphates form <scene name='Shane_Harmon_Sandbox/Atp/5'>hydrogen bonds</scene> with the enzyme.  The 3 hydrogen bonds of ATP are favored over the 2 hydrogen bonds of ADP.
+The general mechanism is a single displacement Sn2 reaction in which the ADP-B-phosphate oxygen atom initiates nucleophilic attack on the 1-phosphate group of 1-3biphosphoglycerate <ref> Auerbach, Gunter et al. 1997. Closed Structure of phosphoglycerate kinase from Thermotoga maritima reveals the catalytic mechanism and determinants of thermal stability. Structure. 5:1475-1483.</ref>.  Thus, the phosphoryl group is transferred directly via a charged transition state.  The product, ATP, is favored because it's negatively charged oxygens of the 3 phosphates form <scene name='Shane_Harmon_Sandbox/Atp/5'>hydrogen bonds</scene> with the enzyme.  The 3 hydrogen bonds of ATP are favored over the 2 hydrogen bonds of ADP.
 [[Image:PGKmechanism2.jpg]]
-Two specific residues known to be necessary for catalysis are <scene name='Shane_Harmon_Sandbox/197_and_38/2'>Lys 197 and Arg 36</scene>.  Lys 197 secures 1,3-biphosphoblycerate in the closed conformation, and it has been proposed that the transition state intermediary is stabilized by the highly conserved Lys 197 as it transfers the phosphate group.  Additionally, it has been shown that Arg 38 is also necessary for catalytic function.  Arg 36 has been shown to stabilize a water molecule in the closed conformation and may form a hydrogen bond with the ATP product.
+Two specific residues known to be necessary for catalysis are <scene name='Shane_Harmon_Sandbox/197_and_38/2'>Lys 197 and Arg 36</scene>.  Lys 197 secures 1,3-biphosphoblycerate in the closed conformation, and it has been proposed that the transition state intermediary is stabilized by the highly conserved Lys 197 as it transfers the phosphate group.  Additionally, it has been shown that Arg 38 is also necessary for catalytic function.  Arg 36 has been shown to stabilize a water molecule in the closed conformation and may form a hydrogen bond with the ATP product <ref> Auerbach, Gunter et al. 1997. Closed Structure of phosphoglycerate kinase from Thermotoga maritima reveals the catalytic mechanism and determinants of thermal stability. Structure. 5:1475-1483.</ref>.