6CTS

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Observed: 0.110 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

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, S.J.

(1990) Biochemistry 29: 2213-2219

  • Primary Citation of Related Structures:  
    5CTS, 6CTS

  • PubMed Abstract: 

    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.


  • Organizational Affiliation

    Institute of Molecular Biology, University of Oregon, Eugene 97403.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CITRATE SYNTHASE433Gallus gallusMutation(s): 0 
EC: 4.1.3.7
UniProt
Find proteins for P23007 (Gallus gallus)
Explore P23007 
Go to UniProtKB:  P23007
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP23007
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CIC
Query on CIC

Download Ideal Coordinates CCD File 
B [auth A]CITRYL-THIOETHER-COENZYME *A
C27 H44 N7 O21 P3 S
VPFUWJMPUQBRCJ-QVYRMQCDSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Observed: 0.110 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 104α = 90
b = 78.1β = 78.9
c = 58.3γ = 90
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1990-10-15
    Type: Initial release
  • Version 1.1: 2008-03-25
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other
  • Version 1.4: 2024-03-13
    Changes: Data collection, Database references, Derived calculations