3N1X

X-ray Crystal Structure of Toluene/o-Xylene Monooxygenase Hydroxylase T201C Mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.187 

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:  
    3N20, 3N1X, 3N1Y, 3N1Z

  • 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, T201C, and T201V variants of ToMOH were prepared by site-directed mutagenesis ...

    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
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Toluene o-xylene monooxygenase componentA498Pseudomonas sp. OX1Mutation(s): 1 
Gene Names: touA
UniProt
Find proteins for Q6IV66 (Pseudomonas sp. OX1)
Explore Q6IV66 
Go to UniProtKB:  Q6IV66
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Toluene o-xylene monooxygenase componentB330Pseudomonas sp. OX1Mutation(s): 0 
Gene Names: touE
UniProt
Find proteins for Q6IV62 (Pseudomonas sp. OX1)
Explore Q6IV62 
Go to UniProtKB:  Q6IV62
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Toluene o-xylene monooxygenase componentC86Pseudomonas sp. OX1Mutation(s): 0 
Gene Names: touB
UniProt
Find proteins for Q6IV65 (Pseudomonas sp. OX1)
Explore Q6IV65 
Go to UniProtKB:  Q6IV65
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
H [auth B]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
EDO
Query on EDO

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G [auth A]1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

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D [auth A], E [auth A]FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
OH
Query on OH

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F [auth A]HYDROXIDE ION
H O
XLYOFNOQVPJJNP-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.187 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 183.294α = 90
b = 183.294β = 90
c = 68.128γ = 120
Software Package:
Software NamePurpose
Blu-Icedata collection
PHASERphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

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