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Overview for MACiE Entry M0078

Version history

General Information

EC Number: 2.3.3.1 (A member of the Transferases, Acyltransferases, Acyl groups converted into alkyl groups on transfer)

Enzyme Name: citrate (Si)-synthase

Biological Species: Gallus gallus (Chicken)

Catalytic Chain UniprotKB Accession Codes:

  • P23007 - Citrate synthase, mitochondrial

Representative PDB Code: 1al6 - CHICKEN CITRATE SYNTHASE COMPLEX WITH N-HYDROXYAMIDO-COA ANDOXALOACETATE (Resolution = 1.85 Å).

Catalytic CATH Codes:

Display structure information

Overall Reaction:

Image of oxaloacetate

Image of acetyl-CoA

Image of water

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Image of CoA

Image of citrate

oxaloacetate
C00036
CHEBI:16452
acetyl-CoA
C00024
CHEBI:57288
water
C00001
CHEBI:15377
CoA
C00010
CHEBI:57287
citrate
C00158
CHEBI:35808

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Stepwise Description of the Reaction

Step 1Asp375 deprotonates the CH3 of acetyl-CoA, with concomitant double bond rearrangement.
Step 2The oxyanion collapses, initiating a nucleophilic attack on the carbonyl carbon of oxaloacetate in an addition reaction with concomitant deprotonation of His320.
Step 3His320 deprotonates water, initiating a nucleophilic attack on the carbonyl carbon of the CoA intermediate in a substitution reaction that eliminates CoA with concomitant deprotonation of Asp375.

View similar reactions (composite manual annotation)


Catalytic Residues Involved

Type Number Chain Location of Function
Ser 244 A Side Chain
His 274 A Side Chain
His 320 A Side Chain
Asp 375 A Side Chain

References

  1. M. Karpusas et al. (1990), Biochemistry, 29, 2213-2219. Proposed mechanism for the condensation reaction of citrate synthase: 1.9-A structure of the ternary complex with oxaloacetate and carboxymethyl coenzyme A.
    Medline: 2337600
  2. C. T. Evans et al. (1996), Biochemistry, 35, 10661-10672. Active site mutants of pig citrate synthase: effects of mutations on the enzyme catalytic and structural properties.
    Medline: 8718855
  3. W. Yang et al. (2003), J. Phys. Chem. B, 107, 5986-5994. Computational Study of the Citrate Synthase Catalyzed Deprotonation of Acetyl-Coenzyme A and Fluoroacetyl-Coenzyme A: Demonstration of a Layered Quantum Mechanical Approach.

Homologue information for M0078 (1al6)

CSA Homologues

MACiE Homologues (within the PDB)

MACiE Homologues (within UniprotKB/SwissProt)


Links to this entry in other databases

Link to EC-PDB-SUM Link to PDB-SUM Link to RCSB PDB Link to PDBe Link to CSA
Link to MetaCyc Link to KEGG Link to BRENDA Link to ExplorENZ
Link to EzCatDB

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citrate (Si)-synthase activity (molecular function)
mitochondrion (cellular component)
mitochondrial matrix (cellular component)
carbohydrate metabolic process (biological process)
tricarboxylic acid cycle (biological process)
transferase activity (molecular function)
cellular carbohydrate metabolic process (biological process)
transferase activity, transferring acyl groups, acyl groups converted into alkyl on transfer (molecular function)
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