4HKA

Crystal structure of Drosophila melanogaster tryptophan 2,3-dioxygenase in complex with HEME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.226 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Crystal structure of Drosophila melanogaster tryptophan 2,3-dioxygenase reveals insights into substrate recognition and catalytic mechanism.

Huang, W.Gong, Z.Li, J.Ding, J.

(2013) J.Struct.Biol. 181: 291-299

  • DOI: 10.1016/j.jsb.2013.01.002

  • PubMed Abstract: 
  • Tryptophan 2,3-dioxygenase (TDO) catalyzes the oxidative cleavage of the indole ring of l-tryptophan to N-formylkynurenine in the kynurenine pathway, and is considered as a drug target for cancer immunotherapy. Here, we report the first crystal struc ...

    Tryptophan 2,3-dioxygenase (TDO) catalyzes the oxidative cleavage of the indole ring of l-tryptophan to N-formylkynurenine in the kynurenine pathway, and is considered as a drug target for cancer immunotherapy. Here, we report the first crystal structure of a eukaryotic TDO from Drosophila melanogaster (DmTDO) in complex with heme at 2.7Å resolution. DmTDO consists of an N-terminal segment, a large domain and a small domain, and assumes a tetrameric architecture. Compared with prokaryotic TDOs, DmTDO contains two major insertion sequences: one forms part of the heme-binding site and the other forms a large portion of the small domain. The small domain which is unique to eukaryotic TDOs, interacts with the active site of an adjacent monomer and plays a role in the catalysis. Molecular modeling and dynamics simulation of DmTDO-heme-Trp suggest that like prokaryotic TDOs, DmTDO adopts an induced-fit mechanism to bind l-Trp; in particular, two conserved but flexible loops undergo conformational changes, converting the active site from an open conformation to a closed conformation. The functional roles of the key residues involved in recognition and binding of the heme and the substrate are verified by mutagenesis and kinetic studies. In addition, a modeling study of DmTDO in complex with the competitive inhibitor LM10 provides useful information for further inhibitor design. These findings reveal insights into the substrate recognition and the catalysis of DmTDO and possibly other eukaryotic TDOs and shed lights on the development of effective anti-TDO inhibitors.


    Organizational Affiliation

    State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Tryptophan 2,3-dioxygenase
A
366Drosophila melanogasterGene Names: v
EC: 1.13.11.11
Find proteins for P20351 (Drosophila melanogaster)
Go to UniProtKB:  P20351
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.226 
  • Space Group: P 64 2 2
Unit Cell:
Length (Å)Angle (°)
a = 114.719α = 90.00
b = 114.719β = 90.00
c = 213.438γ = 120.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
HKL-2000data scaling
PDB_EXTRACTdata extraction
PHASERphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2012-10-15 
  • Released Date: 2013-03-27 
  • Deposition Author(s): Huang, W., Ding, J.

Revision History 

  • Version 1.0: 2013-03-27
    Type: Initial release