2O7R

Plant carboxylesterase AeCXE1 from Actinidia eriantha with acyl adduct


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.199 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

High-Resolution Crystal Structure of Plant Carboxylesterase AeCXE1, from Actinidia eriantha, and Its Complex with a High-Affinity Inhibitor Paraoxon.

Ileperuma, N.R.Marshall, S.D.Squire, C.J.Baker, H.M.Oakeshott, J.G.Russell, R.J.Plummer, K.M.Newcomb, R.D.Baker, E.N.

(2007) Biochemistry 46: 1851-1859

  • DOI: 10.1021/bi062046w
  • Primary Citation of Related Structures:  2O7V

  • PubMed Abstract: 
  • Carboxylesterases (CXEs) are widely distributed in plants, where they have been implicated in roles that include plant defense, plant development, and secondary metabolism. We have cloned, overexpressed, purified, and crystallized a carboxylesterase ...

    Carboxylesterases (CXEs) are widely distributed in plants, where they have been implicated in roles that include plant defense, plant development, and secondary metabolism. We have cloned, overexpressed, purified, and crystallized a carboxylesterase from the kiwifruit species Actinidia eriantha (AeCXE1). The structure of AeCXE1 was determined by X-ray crystallography at 1.4 A resolution. The crystal structure revealed that AeCXE1 is a member of the alpha/beta-hydrolase fold superfamily, most closely related structurally to the hormone-sensitive lipase subgroup. The active site of the enzyme, located in an 11 A deep hydrophobic gorge, contains the conserved catalytic triad residues Ser169, Asp276, and His306. Kinetic analysis using artificial ester substrates showed that the enzyme can hydrolyze a range of carboxylester substrates with acyl groups ranging from C2 to C16, with a preference for butyryl moieties. This preference was supported by the discovery of a three-carbon acyl adduct bound to the active site Ser169 in the native structure. AeCXE1 was also found to be inhibited by organophosphates, with paraoxon (IC50 = 1.1 muM) a more potent inhibitor than dimethylchlorophosphate (DMCP; IC50 = 9.2 muM). The structure of AeCXE1 with paraoxon bound was determined at 2.3 A resolution and revealed that the inhibitor binds covalently to the catalytic serine residue, with virtually no change in the structure of the enzyme. The structural information for AeCXE1 provides a basis for addressing the wider functional roles of carboxylesterases in plants.


    Organizational Affiliation

    School of Biological Sciences, University of Auckland, Auckland, New Zealand.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CXE carboxylesterase
A
338Actinidia erianthaGene Names: CXE1
EC: 3.1.1.1
Find proteins for Q0ZPV7 (Actinidia eriantha)
Go to UniProtKB:  Q0ZPV7
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
4PA
Query on 4PA

Download SDF File 
Download CCD File 
A
PROPYL ACETATE
C5 H10 O2
YKYONYBAUNKHLG-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.199 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 156.565α = 90.00
b = 53.820β = 102.48
c = 42.328γ = 90.00
Software Package:
Software NamePurpose
SOLVEphasing
Blu-Icedata collection
HKL-2000data scaling
HKL-2000data reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-27
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance