4EU8

Succinyl-CoA:acetate CoA-transferase (AarCH6-S71A) in complex with CoA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.81 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.183 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal Structures of Acetobacter aceti Succinyl-Coenzyme A (CoA):Acetate CoA-Transferase Reveal Specificity Determinants and Illustrate the Mechanism Used by Class I CoA-Transferases.

Mullins, E.A.Kappock, T.J.

(2012) Biochemistry 51: 8422-8434

  • DOI: 10.1021/bi300957f
  • Primary Citation of Related Structures:  
    4EUA, 4EUB, 4EUC, 4EU4, 4EU5, 4EU6, 4EU7, 4EU8, 4EU9, 4EU3

  • PubMed Abstract: 
  • Coenzyme A (CoA)-transferases catalyze transthioesterification reactions involving acyl-CoA substrates, using an active-site carboxylate to form covalent acyl anhydride and CoA thioester adducts. Mechanistic studies of class I CoA-transferases suggested that acyl-CoA binding energy is used to accelerate rate-limiting acyl transfers by compressing the substrate thioester tightly against the catalytic glutamate [White, H ...

    Coenzyme A (CoA)-transferases catalyze transthioesterification reactions involving acyl-CoA substrates, using an active-site carboxylate to form covalent acyl anhydride and CoA thioester adducts. Mechanistic studies of class I CoA-transferases suggested that acyl-CoA binding energy is used to accelerate rate-limiting acyl transfers by compressing the substrate thioester tightly against the catalytic glutamate [White, H., and Jencks, W. P. (1976) J. Biol. Chem. 251, 1688-1699]. The class I CoA-transferase succinyl-CoA:acetate CoA-transferase is an acetic acid resistance factor (AarC) with a role in a variant citric acid cycle in Acetobacter aceti. In an effort to identify residues involved in substrate recognition, X-ray crystal structures of a C-terminally His(6)-tagged form (AarCH6) were determined for several wild-type and mutant complexes, including freeze-trapped acetylglutamyl anhydride and glutamyl-CoA thioester adducts. The latter shows the acetate product bound to an auxiliary site that is required for efficient carboxylate substrate recognition. A mutant in which the catalytic glutamate was changed to an alanine crystallized in a closed complex containing dethiaacetyl-CoA, which adopts an unusual curled conformation. A model of the acetyl-CoA Michaelis complex demonstrates the compression anticipated four decades ago by Jencks and reveals that the nucleophilic glutamate is held at a near-ideal angle for attack as the thioester oxygen is forced into an oxyanion hole composed of Gly388 NH and CoA N2″. CoA is nearly immobile along its entire length during all stages of the enzyme reaction. Spatial and sequence conservation of key residues indicates that this mechanism is general among class I CoA-transferases.


    Related Citations: 
    • A specialized citric acid cycle requiring succinyl-coenzyme A (CoA):acetate CoA-transferase (AarC) confers acetic acid resistance on the acidophile Acetobacter aceti
      Mullins, E.A., Francois, J.A., Kappock, T.J.
      (2008) J Bacteriol 190: 4933

    Organizational Affiliation

    Department of Biochemistry, Purdue University, West Lafayette, IN 47907-2063, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Succinyl-CoA:acetate coenzyme A transferaseA, B514Acetobacter acetiMutation(s): 1 
Gene Names: aarC
EC: 2.8.3.18
Find proteins for B3EY95 (Acetobacter aceti)
Explore B3EY95 
Go to UniProtKB:  B3EY95
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.81 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.183 
  • Space Group: P 21 21 21
  • Diffraction Data DOI: 10.15785/SBGRID/276 SBGrid
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 67.276α = 90
b = 109.667β = 90
c = 120.067γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-10-10
    Type: Initial release
  • Version 1.1: 2012-11-07
    Changes: Database references
  • Version 1.2: 2017-11-15
    Changes: Refinement description