4FNM

The alpha-esterase-7 carboxylesterase, E3, from the blowfly Lucilia cuprina


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.804 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.170 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Structure and function of an insect alpha-carboxylesterase ( alpha Esterase7) associated with insecticide resistance.

Jackson, C.J.Liu, J.W.Carr, P.D.Younus, F.Coppin, C.Meirelles, T.Lethier, M.Pandey, G.Ollis, D.L.Russell, R.J.Weik, M.Oakeshott, J.G.

(2013) Proc.Natl.Acad.Sci.USA 110: 10177-10182

  • DOI: 10.1073/pnas.1304097110
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Insect carboxylesterases from the αEsterase gene cluster, such as αE7 (also known as E3) from the Australian sheep blowfly Lucilia cuprina (LcαE7), play an important physiological role in lipid metabolism and are implicated in the detoxification of o ...

    Insect carboxylesterases from the αEsterase gene cluster, such as αE7 (also known as E3) from the Australian sheep blowfly Lucilia cuprina (LcαE7), play an important physiological role in lipid metabolism and are implicated in the detoxification of organophosphate (OP) insecticides. Despite the importance of OPs to agriculture and the spread of insect-borne diseases, the molecular basis for the ability of α-carboxylesterases to confer OP resistance to insects is poorly understood. In this work, we used laboratory evolution to increase the thermal stability of LcαE7, allowing its overexpression in Escherichia coli and structure determination. The crystal structure reveals a canonical α/β-hydrolase fold that is very similar to the primary target of OPs (acetylcholinesterase) and a unique N-terminal α-helix that serves as a membrane anchor. Soaking of LcαE7 crystals in OPs led to the capture of a crystallographic snapshot of LcαE7 in its phosphorylated state, which allowed comparison with acetylcholinesterase and rationalization of its ability to protect insects against the effects of OPs. Finally, inspection of the active site of LcαE7 reveals an asymmetric and hydrophobic substrate binding cavity that is well-suited to fatty acid methyl esters, which are hydrolyzed by the enzyme with specificity constants (∼10(6) M(-1) s(-1)) indicative of a natural substrate.


    Organizational Affiliation

    Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia. cjackson@rsc.anu.edu.au




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
E3 alpha-esterase-7 carboxylesterase
A
569Lucilia cuprinaMutation(s): 6 
Gene Names: LcaE7
EC: 3.1.1.-
Find proteins for Q25252 (Lucilia cuprina)
Go to UniProtKB:  Q25252
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DPF
Query on DPF

Download SDF File 
Download CCD File 
A
DIETHYL HYDROGEN PHOSPHATE
C4 H11 O4 P
UCQFCFPECQILOL-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.804 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.170 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 50.650α = 90.00
b = 102.740β = 90.00
c = 226.400γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
XSCALEdata scaling
ADSCdata collection
XDSdata reduction
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-12-04
    Type: Initial release