3GE3

Crystal Structure of the reduced Toluene 4-Monooxygenase HD T201A mutant complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.52 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.168 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Role for threonine 201 in the catalytic cycle of the soluble diiron hydroxylase toluene 4-monooxygenase.

Elsen, N.L.Bailey, L.J.Hauser, A.D.Fox, B.G.

(2009) Biochemistry 48: 3838-3846

  • DOI: 10.1021/bi900144a
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The active site residue Thr-201 in toluene 4-monooxygenase hydroxylase (T4moH) has a structural counterpart in the active sites of all diiron monooxygenases. Thus, our previous finding that mutation of this residue to Ala, Gly, or Ser had no impact o ...

    The active site residue Thr-201 in toluene 4-monooxygenase hydroxylase (T4moH) has a structural counterpart in the active sites of all diiron monooxygenases. Thus, our previous finding that mutation of this residue to Ala, Gly, or Ser had no impact on steady-state catalysis or coupling was surprising. In this work, we provide kinetic, biochemical, and structural evidence that one role of Thr-201 may be to stabilize a peroxo-level intermediate during enzyme catalysis. During reactions in the absence of substrate, T201 T4moH slowly consumed O(2) but only a negligible amount of H(2)O(2) was released. In contrast, T201A T4moH gave stoichometric release of H(2)O(2) during reaction in the absence of substrate. Both enzyme isoforms were tightly coupled during steady-state catalysis with saturating toluene and other optimal substrates and exhibited near-identical kinetic parameters. However, rapid mix single-turnover studies showed that T201A T4moH had a faster first-order rate constant for product formation than T201 T4moH did. Comparison of X-ray crystal structures of resting and reduced T201A T4moH in complex with T4moD with comparable structures of T201 T4moHD revealed changes in the positions of several key active site residues relative to the comparable structures of T201 T4moH with T4moD. This combination of catalytic and structural studies offers important new insight into the role of the role of conserved Thr-201, and its contributions to the catalytic reaction cycle.


    Organizational Affiliation

    Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison, Wisconsin 53706-1544, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Toluene-4-monooxygenase system protein A
A
500Pseudomonas mendocinaMutation(s): 1 
Gene Names: tmoA
EC: 1.14.13.236
Find proteins for Q00456 (Pseudomonas mendocina)
Go to UniProtKB:  Q00456
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Toluene-4-monooxygenase system protein E
B
327Pseudomonas mendocinaMutation(s): 0 
Gene Names: tmoE
EC: 1.14.13.236
Find proteins for Q00460 (Pseudomonas mendocina)
Go to UniProtKB:  Q00460
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Toluene-4-monooxygenase system protein B
C
84Pseudomonas mendocinaMutation(s): 0 
Gene Names: tmoB
EC: 1.14.13.236
Find proteins for Q00457 (Pseudomonas mendocina)
Go to UniProtKB:  Q00457
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
Toluene-4-monooxygenase system protein D
E
103Pseudomonas mendocinaMutation(s): 0 
Gene Names: tmoD
Find proteins for Q00459 (Pseudomonas mendocina)
Go to UniProtKB:  Q00459
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download SDF File 
Download CCD File 
A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
FE
Query on FE

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.52 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.168 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 100.260α = 90.00
b = 115.966β = 90.00
c = 180.137γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data collection
HKL-2000data scaling
REFMACrefinement
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2014-07-02
    Type: Structure summary