PDBsum entry 3kv8

Hydrolase

PDB id: 3kv8

Contents

Protein chains

133 a.a. *

Ligands

FAH ×6

Waters ×218

* Residue conservation analysis

PDB id:

3kv8

Name:

Hydrolase

Title:

Structural basis of the activity and substrate specificity of the fluoroacetyl-coa thioesterase flk - wild type flk in complex with fluoro-acetate

Structure:

Fluoroacetyl-coa thioesterase flk. Chain: a, b. Fragment: flk. Engineered: yes

Source:

Streptomyces cattleya. Organism_taxid: 29303. Gene: flk, fluoroacetyl-coa thioesterase flk. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

1.85Å R-factor: 0.172 R-free: 0.228

Authors:

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

Key ref:

M.V.Dias et al. (2010). Structural basis for the activity and substrate specificity of fluoroacetyl-CoA thioesterase FlK. J Biol Chem, 285, 22495-22504. PubMed id: 20430898 DOI: 10.1074/jbc.M110.107177

Date:

29-Nov-09 Release date: 21-Apr-10

Protein chains

Q1EMV2  (FLK_STRCT) -  Fluoroacetyl-CoA thioesterase from Streptantibioticus cattleyicolor

Seq: 139 a.a.

Struc: 133 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.2.29 - fluoroacetyl-CoA thioesterase.
• Reaction: fluoroacetyl-CoA + H2O = fluoroacetate + CoA + H⁺

fluoroacetyl-CoA + H2O = fluoroacetate + CoA (Bound ligand (Het Group name = FAH) corresponds exactly) + H(+)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1074/jbc.M110.107177

J Biol Chem 285:22495-22504 (2010)

PubMed id: 20430898

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

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

ABSTRACT

The thioesterase FlK from the fluoroacetate-producing Streptomyces cattleya catalyzes the hydrolysis of fluoroacetyl-coenzyme A. This provides an effective self-defence 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 Thr42, His76 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 Arg120 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.