3NTJ

Redox regulation of Plasmodium falciparum ornithine delta-aminotransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Redox regulation of Plasmodium falciparum ornithine delta-aminotransferase

Jortzik, E.Fritz-Wolf, K.Sturm, N.Hipp, M.Rahlfs, S.Becker, K.

(2010) J.Mol.Biol. 402: 445-459

  • DOI: 10.1016/j.jmb.2010.07.039
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Ornithine δ-aminotransferase (OAT) of the malaria parasite Plasmodium falciparum catalyzes the reversible conversion of ornithine into glutamate-5-semialdehyde and glutamate and is-in contrast to its human counterpart-activated by thioredoxin (Trx) b ...

    Ornithine δ-aminotransferase (OAT) of the malaria parasite Plasmodium falciparum catalyzes the reversible conversion of ornithine into glutamate-5-semialdehyde and glutamate and is-in contrast to its human counterpart-activated by thioredoxin (Trx) by a factor of 10. Trx, glutaredoxin, and plasmoredoxin are redox-active proteins that play a crucial role in the maintenance and control of redox reactions, and were shown to interact with P. falciparum OAT. OAT, which is involved in ornithine homeostasis and proline biosynthesis, is essential for mitotic cell division in rapidly growing cells, thus representing a potential target for chemotherapeutic intervention. Here we report the three-dimensional crystal structure of P. falciparum OAT at 2.3 Å resolution. The overall structure is very similar to that of the human OAT. However, in plasmodial OAT, the loop involved in substrate binding contains two cysteine residues, which are lacking in human OAT. Site-directed mutagenesis of these cysteines and functional analysis demonstrated that Cys154 and Cys163 mediate the interaction with Trx. Interestingly, the Cys154→Ser mutant has a strongly reduced specific activity, most likely due to impaired binding of ornithine. Cys154 and Cys163 are highly conserved in Plasmodium but do not exist in other organisms, suggesting that redox regulation of OAT by Trx is specific for malaria parasites. Plasmodium might require a tight Trx-mediated control of OAT activity for coordinating ornithine homeostasis, polyamine synthesis, proline synthesis, and mitotic cell division.


    Organizational Affiliation

    Interdisciplinary Research Center, Justus-Liebig-University, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ornithine aminotransferase
A, B, C, D
422Plasmodium falciparum (isolate 3D7)Mutation(s): 0 
Gene Names: OAT
EC: 2.6.1.13
Find proteins for Q6LFH8 (Plasmodium falciparum (isolate 3D7))
Go to Gene View: OAT
Go to UniProtKB:  Q6LFH8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, C
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.191 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 101.390α = 90.00
b = 104.970β = 90.00
c = 181.460γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXphasing
PHENIXmodel building
XDSdata reduction
XDSdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-08-04
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance