Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 30.56 kDa 
• Atom Count: 2228 
• Residue Count: 266 
• Unique protein chains: 1

3KX7

Structural basis of the activity and substrate specificity of the fluoroacetyl-CoA FlK - apo wild type FlK

• DOI: 10.2210/pdb3KX7/pdb

• Classification: HYDROLASE
• Organism(s): Streptomyces cattleya
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2009-12-02 Released: 2010-04-21 
• Deposition Author(s): Dias, M.V.B., Huang, F., Chirgadze, D.Y., Tosin, M., Spiteller, D., Valentine, E.F., Leadlay, P.F., Spencer, J.B., Blundell, T.L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Free: 0.232 
• R-Value Work: 0.196 
• R-Value Observed: 0.198 

Literature

Structural basis for the activity and substrate specificity of fluoroacetyl-CoA thioesterase FlK.

Dias, M.V., Huang, F., Chirgadze, D.Y., Tosin, M., Spiteller, D., Dry, E.F., Leadlay, P.F., Spencer, J.B., Blundell, T.L.

(2010) J Biol Chem 285: 22495-22504

• PubMed: 20430898 
• DOI: 10.1074/jbc.M110.107177
• Primary Citation of Related Structures:  
  3KUV, 3KV7, 3KUW, 3KV8, 3KVZ, 3KW1, 3KVU, 3KVI, 3KX8, 3KX7


• PubMed Abstract: 
  

The thioesterase FlK from the fluoroacetate-producing Streptomyces cattleya catalyzes the hydrolysis of fluoroacetyl-coenzyme A. This provides an effective self-defense mechanism, preventing any fluoroacetyl-coenzyme A formed from being further metabolized to 4-hydroxy-trans-aconitate, a lethal inhibitor of the tricarboxylic acid cycle. Remarkably, FlK does not accept acetyl-coenzyme A as a substrate. Crystal structure analysis shows that FlK forms a dimer, in which each subunit adopts a hot dog fold as observed for type II thioesterases. Unlike other type II thioesterases, which invariably utilize either an aspartate or a glutamate as catalytic base, we show by site-directed mutagenesis and crystallography that FlK employs a catalytic triad composed of Thr(42), His(76), and a water molecule, analogous to the Ser/Cys-His-acid triad of type I thioesterases. Structural comparison of FlK complexed with various substrate analogues suggests that the interaction between the fluorine of the substrate and the side chain of Arg(120) located opposite to the catalytic triad is essential for correct coordination of the substrate at the active site and therefore accounts for the substrate specificity.

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Organizational Affiliation: 

Department of Biochemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Fluoroacetyl-CoA thioesterase FlK	A, B	139	Streptomyces cattleya	Mutation(s): 0  Gene Names: flK, fluoroacetyl-CoA thioesterase FlK EC: 3 (PDB Primary Data), 3.1.2.29 (UniProt)
Find proteins for Q1EMV2 (Streptomyces cattleya) Explore Q1EMV2  Go to UniProtKB:  Q1EMV2

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Free: 0.232 
• R-Value Work: 0.196 
• R-Value Observed: 0.198 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 48.211	α = 90
b = 90.858	β = 100.42
c = 61.787	γ = 90

Software Package:

Software Name	Purpose
ADSC	data collection
AMoRE	phasing
REFMAC	refinement
DENZO	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-12-02 
• Released Date: 2010-04-21 
Deposition Author(s): Dias, M.V.B., Huang, F., Chirgadze, D.Y., Tosin, M., Spiteller, D., Valentine, E.F., Leadlay, P.F., Spencer, J.B., Blundell, T.L.

Revision History 

• Version 1.0: 2010-04-21
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance
• Version 1.2: 2018-01-24
  Changes: Structure summary