2XMB

G117H mutant of human butyrylcholinesterase in complex with sulfate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.168 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

X-Ray Crystallographic Snapshots of Reaction Intermediates in the G117H Mutant of Human Butyrylcholinesterase, a Nerve Agent Target Engineered Into a Catalytic Bioscavenge

Nachon, F.Carletti, E.Wandhammer, M.Nicolet, Y.Schopfer, L.M.Masson, P.Lockridge, O.

(2011) Biochem.J. 434: 73

  • DOI: 10.1042/BJ20101648
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • OPs (organophosphylates) exert their acute toxicity through inhibition of acetylcholinesterase, by phosphylation of the catalytic serine residue. Engineering of human butyrylcholinesterase, by substitution of a histidine residue for the glycine resid ...

    OPs (organophosphylates) exert their acute toxicity through inhibition of acetylcholinesterase, by phosphylation of the catalytic serine residue. Engineering of human butyrylcholinesterase, by substitution of a histidine residue for the glycine residue at position 117, led to the creation of OP hydrolase activity. However, the lack of structural information and poor understanding of the hydrolytic mechanism of the G117H mutant has hampered further improvements in the catalytic activity. We have solved the crystallographic structure of the G117H mutant with a variety of ligands in its active site. A sulfate anion bound to the active site suggested the positioning for an OP prior to phosphylation. A fluoride anion was found in the active site when NaF was added to the crystallization buffer. In the fluoride complex, the imidazole ring from the His117 residue was substantially shifted, adopting a relaxed conformation probably close to that of the unliganded mutant enzyme. Additional X-ray structures were obtained from the transient covalent adducts formed upon reaction of the G117H mutant with the OPs echothiophate and VX [ethyl ({2-[bis(propan-2-yl)amino]ethyl}sulfanyl](methyl)phosphinate]. The position of the His117 residue shifted in response to the introduction of these adducts, overlaying the phosphylserine residue. These structural data suggest that the dephosphylation mechanism involves either a substantial conformational change of the His117 residue or an adjacent nucleophilic substitution by water.


    Organizational Affiliation

    Cellule Enzymologie, Département de Toxicologie, Institut de Recherche Biomédicale des Armées-CRSSA, 24 avenue des Maquis du Grésivaudan, La Tronche, France. florian@nachon.net




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CHOLINESTERASE
A
529Homo sapiensMutation(s): 5 
Gene Names: BCHE (CHE1)
EC: 3.1.1.8
Find proteins for P06276 (Homo sapiens)
Go to Gene View: BCHE
Go to UniProtKB:  P06276
Small Molecules
Ligands 7 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

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A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CL
Query on CL

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A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
GOL
Query on GOL

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A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
UNX
Query on UNX

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A
UNKNOWN ATOM OR ION
X
*
 Ligand Interaction
NAG
Query on NAG

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A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
FUL
Query on FUL

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A
BETA-L-FUCOSE
6-DEOXY-BETA-L-GALACTOSE
C6 H12 O5
SHZGCJCMOBCMKK-KGJVWPDLSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.168 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 154.800α = 90.00
b = 154.800β = 90.00
c = 134.650γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
XDSdata reduction
XSCALEdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-12-01
    Type: Initial release
  • Version 1.1: 2011-11-16
    Type: Database references, Non-polymer description, Refinement description, Version format compliance