Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Biological Assembly 2  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

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

Biological assembly 2 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 65.50 kDa 
• Atom Count: 5090 
• Modelled Residue Count: 569 
• Deposited Residue Count: 569 
• Unique protein chains: 1

4FNM

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

• PDB DOI: 10.2210/pdb4FNM/pdb

• Classification: HYDROLASE
• Organism(s): Lucilia cuprina
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2012-06-20 Released: 2013-12-04 
• Deposition Author(s): Jackson, C.J., Liu, J.-W., Carr, P.D., Younis, F., Pandey, G., Coppin, C., Meirelles, T., Ollis, D.L., Tawfik, D.S., Weik, M., Oakeshott, J.G.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.204 
• R-Value Work: 0.170 
• R-Value Observed: 0.171 

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 U S A 110: 10177-10182

• PubMed: 23733941 
• DOI: 10.1073/pnas.1304097110
• Primary Citation of Related Structures:  
  4FNG, 4FNM


• 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 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.

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Organizational Affiliation: 

Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
E3 alpha-esterase-7 carboxylesterase	A	569	Lucilia cuprina	Mutation(s): 6  Gene Names: LcaE7 EC: 3.1.1
UniProt
Find proteins for Q25252 (Lucilia cuprina) Explore Q25252  Go to UniProtKB:  Q25252

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
DPF	B [auth A]	DIETHYL HYDROGEN PHOSPHATE C4 H11 O4 P UCQFCFPECQILOL-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.204 
• R-Value Work: 0.170 
• R-Value Observed: 0.171 
• Space Group: C 2 2 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 50.65	α = 90
b = 102.74	β = 90
c = 226.4	γ = 90

Software Package:

Software Name	Purpose
ADSC	data collection
PHASER	phasing
PHENIX	refinement
XDS	data reduction
XSCALE	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2012-06-20 
• Released Date: 2013-12-04 
Deposition Author(s): Jackson, C.J., Liu, J.-W., Carr, P.D., Younis, F., Pandey, G., Coppin, C., Meirelles, T., Ollis, D.L., Tawfik, D.S., Weik, M., Oakeshott, J.G.

Revision History  

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