5cts: Difference between revisions

Revision as of 20:15, 21 February 2008

PROPOSED MECHANISM FOR THE CONDENSATION REACTION OF CITRATE SYNTHASE. 1.9-ANGSTROMS STRUCTURE OF THE TERNARY COMPLEX WITH OXALOACETATE AND CARBOXYMETHYL COENZYME A

OverviewOverview

The crystal structure of the ternary complex citrate synthase-oxaloacetate-carboxymethyl coenzyme A has been solved to a resolution of 1.9 A and refined to a conventional crystallographic R factor of 0.185. The structure resembles a proposed transition state of the condensation reaction and suggests that the condensation reaction proceeds through a neutral enol rather than an enolate intermediate. A mechanism for the condensation reaction is proposed which involves the participation of three key catalytic groups (Asp 375, His 274, and His 320) in two distinct steps. The proposed mechanism invokes concerted general acid-base catalysis twice to explain both the energetics of the reaction and the experimentally observed inversion of stereochemistry at the attacking carbon atom.

About this StructureAbout this Structure

5CTS is a Single protein structure of sequence from Gallus gallus with and as ligands. Active as Citrate (Si)-synthase, with EC number 2.3.3.1 Full crystallographic information is available from OCA.

ReferenceReference

Proposed mechanism for the condensation reaction of citrate synthase: 1.9-A structure of the ternary complex with oxaloacetate and carboxymethyl coenzyme A., Karpusas M, Branchaud B, Remington SJ, Biochemistry. 1990 Mar 6;29(9):2213-9. PMID:2337600

Page seeded by OCA on Thu Feb 21 19:15:02 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

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-[[Image:5cts.gif|left|200px]]<br /><applet load="5cts" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:5cts.gif|left|200px]]<br /><applet load="5cts" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="5cts, resolution 1.9&Aring;" />
 '''PROPOSED MECHANISM FOR THE CONDENSATION REACTION OF CITRATE SYNTHASE. 1.9-ANGSTROMS STRUCTURE OF THE TERNARY COMPLEX WITH OXALOACETATE AND CARBOXYMETHYL COENZYME A'''<br />
 ==Overview==
-The crystal structure of the ternary complex citrate, synthase-oxaloacetate-carboxymethyl coenzyme A has been solved to a, resolution of 1.9 A and refined to a conventional crystallographic R, factor of 0.185. The structure resembles a proposed transition state of, the condensation reaction and suggests that the condensation reaction, proceeds through a neutral enol rather than an enolate intermediate. A, mechanism for the condensation reaction is proposed which involves the, participation of three key catalytic groups (Asp 375, His 274, and His, 320) in two distinct steps. The proposed mechanism invokes concerted, general acid-base catalysis twice to explain both the energetics of the, reaction and the experimentally observed inversion of stereochemistry at, the attacking carbon atom.
+The crystal structure of the ternary complex citrate synthase-oxaloacetate-carboxymethyl coenzyme A has been solved to a resolution of 1.9 A and refined to a conventional crystallographic R factor of 0.185. The structure resembles a proposed transition state of the condensation reaction and suggests that the condensation reaction proceeds through a neutral enol rather than an enolate intermediate. A mechanism for the condensation reaction is proposed which involves the participation of three key catalytic groups (Asp 375, His 274, and His 320) in two distinct steps. The proposed mechanism invokes concerted general acid-base catalysis twice to explain both the energetics of the reaction and the experimentally observed inversion of stereochemistry at the attacking carbon atom.
 ==About this Structure==
-CTS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with OAA and CMC as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Citrate_(Si)-synthase Citrate (Si)-synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.3.1 2.3.3.1] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=5CTS OCA].
+CTS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with <scene name='pdbligand=OAA:'>OAA</scene> and <scene name='pdbligand=CMC:'>CMC</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Citrate_(Si)-synthase Citrate (Si)-synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.3.1 2.3.3.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5CTS OCA].
 ==Reference==
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 [[Category: Branchaud, B.]]
 [[Category: Karpusas, M.]]
-[[Category: Remington, S.J.]]
+[[Category: Remington, S J.]]
 [[Category: CMC]]
 [[Category: OAA]]
 [[Category: oxo-acid-lyase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 19:28:07 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:15:02 2008''