3UPM

Crystal Structure of PTE mutant H254Q/H257F/K185R/I274N


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.201 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Enzymes for the homeland defense: optimizing phosphotriesterase for the hydrolysis of organophosphate nerve agents.

Tsai, P.C.Fox, N.Bigley, A.N.Harvey, S.P.Barondeau, D.P.Raushel, F.M.

(2012) Biochemistry 51: 6463-6475

  • DOI: 10.1021/bi300811t
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Phosphotriesterase (PTE) from soil bacteria is known for its ability to catalyze the detoxification of organophosphate pesticides and chemical warfare agents. Most of the organophosphate chemical warfare agents are a mixture of two stereoisomers at t ...

    Phosphotriesterase (PTE) from soil bacteria is known for its ability to catalyze the detoxification of organophosphate pesticides and chemical warfare agents. Most of the organophosphate chemical warfare agents are a mixture of two stereoisomers at the phosphorus center, and the S(P)-enantiomers are significantly more toxic than the R(P)-enantiomers. In previous investigations, PTE variants were created through the manipulation of the substrate binding pockets and these mutants were shown to have greater catalytic activities for the detoxification of the more toxic S(P)-enantiomers of nerve agent analogues for GB, GD, GF, VX, and VR than the less toxic R(P)-enantiomers. In this investigation, alternate strategies were employed to discover additional PTE variants with significant improvements in catalytic activities relative to that of the wild-type enzyme. Screening and selection techniques were utilized to isolate PTE variants from randomized libraries and site specific modifications. The catalytic activities of these newly identified PTE variants toward the S(P)-enantiomers of chromophoric analogues of GB, GD, GF, VX, and VR have been improved up to 15000-fold relative to that of the wild-type enzyme. The X-ray crystal structures of the best PTE variants were determined. Characterization of these mutants with the authentic G-type nerve agents has confirmed the expected improvements in catalytic activity against the most toxic enantiomers of GB, GD, and GF. The values of k(cat)/K(m) for the H257Y/L303T (YT) mutant for the hydrolysis of GB, GD, and GF were determined to be 2 × 10(6), 5 × 10(5), and 8 × 10(5) M(-1) s(-1), respectively. The YT mutant is the most proficient enzyme reported thus far for the detoxification of G-type nerve agents. These results support a combinatorial strategy of rational design and directed evolution as a powerful tool for the discovery of more efficient enzymes for the detoxification of organophosphate nerve agents.


    Organizational Affiliation

    Department of Chemistry, P.O. Box 30012, Texas A&M University, College Station, TX 77842, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Parathion hydrolase
A, B
327Brevundimonas diminutaMutation(s): 4 
Gene Names: opd
EC: 3.1.8.1
Find proteins for P0A434 (Brevundimonas diminuta)
Go to UniProtKB:  P0A434
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CO
Query on CO

Download SDF File 
Download CCD File 
A, B
COBALT (II) ION
Co
XLJKHNWPARRRJB-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
KCX
Query on KCX
A, B
L-PEPTIDE LINKINGC7 H14 N2 O4LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.201 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 85.563α = 90.00
b = 85.387β = 90.00
c = 88.265γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
PHASERphasing
HKL-2000data reduction
CNSrefinement
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-08-01
    Type: Initial release
  • Version 1.1: 2012-10-03
    Type: Database references