Citrate Synthase: Difference between revisions

Line 6:

'''Mechanism:''' The reaction mechanism for citrate synthase was proposed by James Remington. In this mechanism, three ionizable side chains in the

<scene name='Daniel_Eddelman_Sandbox_2/Cts_active_site/4'>active site</scene> of citrate synthase participate in acid-base catalysis: His 274, His 320, and Asp 375. First, <scene name='Daniel_Eddelman_Sandbox_2/Asp_375/1'>Asp 375</scene> (a base) removes a proton from the methyl group of acetyl-CoA to form its enol. <scene name='Daniel_Eddelman_Sandbox_2/His_274/1'>His 274</scene> stabilizes the acetyl-CoA enolate by forming a hydrogen bond with the enolate oxygen. The enolate then nucleophilically attacks oxaloacetate’s carbonyl carbon, and His 320 donates a proton to oxaloacetate’s carbonyl group in a concerted step, forming citryl-CoA (which remains bound to the enzyme). Finally, citryl-CoA is hydrolyzed to citrate and CoA.

<scene name='Daniel_Eddelman_Sandbox_2/Cts_active_site/4'>active site</scene> of citrate synthase participate in acid-base catalysis: His 274, His 320, and Asp 375. First, <scene name='Daniel_Eddelman_Sandbox_2/Asp_375/1'>Asp 375</scene> (a base) removes a proton from the methyl group of acetyl-CoA to form its enol. <scene name='Daniel_Eddelman_Sandbox_2/His_274/1'>His 274</scene> stabilizes the acetyl-CoA enolate by forming a hydrogen bond with the enolate oxygen. The enolate then nucleophilically attacks oxaloacetate’s carbonyl carbon, and

<scene name='Daniel_Eddelman_Sandbox_2/His_320/1'>His 320</scene> donates a proton to oxaloacetate’s carbonyl group in a concerted step, forming citryl-CoA (which remains bound to the enzyme). Finally, citryl-CoA is hydrolyzed to citrate and CoA.

Citrate Synthase: Difference between revisions

Navigation menu

Page actions

Page actions

Personal tools

Navigation

Search

Tools

@@ Line 6: / Line 6: @@
 '''Mechanism:''' The reaction mechanism for citrate synthase was proposed by James Remington.  In this mechanism, three ionizable side chains in the
-<scene name='Daniel_Eddelman_Sandbox_2/Cts_active_site/4'>active site</scene> of citrate synthase participate in acid-base catalysis: His 274, His 320, and Asp 375.  First, <scene name='Daniel_Eddelman_Sandbox_2/Asp_375/1'>Asp 375</scene> (a base) removes a proton from the methyl group of acetyl-CoA to form its enol.  <scene name='Daniel_Eddelman_Sandbox_2/His_274/1'>His 274</scene> stabilizes the acetyl-CoA enolate by forming a hydrogen bond with the enolate oxygen.  The enolate then nucleophilically attacks oxaloacetate’s carbonyl carbon, and His 320 donates a proton to oxaloacetate’s carbonyl group in a concerted step, forming citryl-CoA (which remains bound to the enzyme).  Finally, citryl-CoA is hydrolyzed to citrate and CoA.
+<scene name='Daniel_Eddelman_Sandbox_2/Cts_active_site/4'>active site</scene> of citrate synthase participate in acid-base catalysis: His 274, His 320, and Asp 375.  First, <scene name='Daniel_Eddelman_Sandbox_2/Asp_375/1'>Asp 375</scene> (a base) removes a proton from the methyl group of acetyl-CoA to form its enol.  <scene name='Daniel_Eddelman_Sandbox_2/His_274/1'>His 274</scene> stabilizes the acetyl-CoA enolate by forming a hydrogen bond with the enolate oxygen.  The enolate then nucleophilically attacks oxaloacetate’s carbonyl carbon, and
+<scene name='Daniel_Eddelman_Sandbox_2/His_320/1'>His 320</scene> donates a proton to oxaloacetate’s carbonyl group in a concerted step, forming citryl-CoA (which remains bound to the enzyme).  Finally, citryl-CoA is hydrolyzed to citrate and CoA.