2O7R

Plant carboxylesterase AeCXE1 from Actinidia eriantha with acyl adduct


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.200 

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: https://doi.org/10.1021/bi062046w
  • Primary Citation of Related Structures:  
    2O7R, 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 from the kiwifruit species Actinidia eriantha (AeCXE1) ...

    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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CXE carboxylesteraseA338Actinidia erianthaMutation(s): 0 
Gene Names: CXE1
EC: 3.1.1.1
UniProt
Find proteins for Q0ZPV7 (Actinidia eriantha)
Explore Q0ZPV7 
Go to UniProtKB:  Q0ZPV7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ0ZPV7
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
4PA
Query on 4PA

Download Ideal Coordinates CCD File 
B [auth A]PROPYL ACETATE
C5 H10 O2
YKYONYBAUNKHLG-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.200 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 156.565α = 90
b = 53.82β = 102.48
c = 42.328γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
Blu-Icedata collection
HKL-2000data reduction
HKL-2000data scaling
SOLVEphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

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