3N20

X-ray Crystal Structure of Toluene/o-Xylene Monooxygenase Hydroxylase T201V Mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Active Site Threonine Facilitates Proton Transfer during Dioxygen Activation at the Diiron Center of Toluene/o-Xylene Monooxygenase Hydroxylase.

Song, W.J.McCormick, M.S.Behan, R.K.Sazinsky, M.H.Jiang, W.Lin, J.Krebs, C.Lippard, S.J.

(2010) J.Am.Chem.Soc. 132: 13582-13585

  • DOI: 10.1021/ja1063795
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Toluene/o-xylene monooxygenase hydroxylase (ToMOH), a diiron-containing enzyme, can activate dioxygen to oxidize aromatic substrates. To elucidate the role of a strictly conserved T201 residue during dioxygen activation of the enzyme, T201S, T201G, T ...

    Toluene/o-xylene monooxygenase hydroxylase (ToMOH), a diiron-containing enzyme, can activate dioxygen to oxidize aromatic substrates. To elucidate the role of a strictly conserved T201 residue during dioxygen activation of the enzyme, T201S, T201G, T201C, and T201V variants of ToMOH were prepared by site-directed mutagenesis. X-ray crystal structures of all the variants were obtained. Steady-state activity, regiospecificity, and single-turnover yields were also determined for the T201 mutants. Dioxygen activation by the reduced T201 variants was explored by stopped-flow UV-vis and Mössbauer spectroscopy. These studies demonstrate that the dioxygen activation mechanism is preserved in all T201 variants; however, both the formation and decay kinetics of a peroxodiiron(III) intermediate, T201(peroxo), were greatly altered, revealing that T201 is critically involved in dioxygen activation. A comparison of the kinetics of O(2) activation in the T201S, T201C, and T201G variants under various reaction conditions revealed that T201 plays a major role in proton transfer, which is required to generate the peroxodiiron(III) intermediate. A mechanism is postulated for dioxygen activation, and possible structures of oxygenated intermediates are discussed.


    Organizational Affiliation

    Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Toluene o-xylene monooxygenase component
A
498Pseudomonas sp. OX1Mutation(s): 1 
Gene Names: touA
Find proteins for Q6IV66 (Pseudomonas sp. OX1)
Go to UniProtKB:  Q6IV66
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Toluene o-xylene monooxygenase component
B
330Pseudomonas sp. OX1Mutation(s): 0 
Gene Names: touE
Find proteins for Q6IV62 (Pseudomonas sp. OX1)
Go to UniProtKB:  Q6IV62
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Toluene o-xylene monooxygenase component
C
86Pseudomonas sp. OX1Mutation(s): 0 
Gene Names: touB
Find proteins for Q6IV65 (Pseudomonas sp. OX1)
Go to UniProtKB:  Q6IV65
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A, B
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
P6G
Query on P6G

Download SDF File 
Download CCD File 
A
HEXAETHYLENE GLYCOL
POLYETHYLENE GLYCOL PEG400
C12 H26 O7
IIRDTKBZINWQAW-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

Download SDF File 
Download CCD File 
A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.218 
  • R-Value Work: 0.206 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 182.889α = 90.00
b = 182.889β = 90.00
c = 68.578γ = 120.00
Software Package:
Software NamePurpose
EPMRphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling
Blu-Icedata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-10-13
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance