4OLC

Carbamate kinase from Giardia lamblia thiocarbamoylated by disulfiram on Cys242


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural Basis for Inactivation of Giardia lamblia Carbamate Kinase by Disulfiram.

Galkin, A.Kulakova, L.Lim, K.Chen, C.Z.Zheng, W.Turko, I.V.Herzberg, O.

(2014) J.Biol.Chem. 289: 10502-10509

  • DOI: 10.1074/jbc.M114.553123

  • PubMed Abstract: 
  • Carbamate kinase from Giardia lamblia is an essential enzyme for the survival of the organism. The enzyme catalyzes the final step in the arginine dihydrolase pathway converting ADP and carbamoyl phosphate to ATP and carbamate. We previously reported ...

    Carbamate kinase from Giardia lamblia is an essential enzyme for the survival of the organism. The enzyme catalyzes the final step in the arginine dihydrolase pathway converting ADP and carbamoyl phosphate to ATP and carbamate. We previously reported that disulfiram, a drug used to treat chronic alcoholism, inhibits G. lamblia CK and kills G. lamblia trophozoites in vitro at submicromolar IC50 values. Here, we examine the structural basis for G. lamblia CK inhibition of disulfiram and its analog, thiram, their activities against both metronidazole-susceptible and metronidazole-resistant G. lamblia isolates, and their efficacy in a mouse model of giardiasis. The crystal structure of G. lamblia CK soaked with disulfiram revealed that the compound thiocarbamoylated Cys-242, a residue located at the edge of the active site. The modified Cys-242 prevents a conformational transition of a loop adjacent to the ADP/ATP binding site, which is required for the stacking of Tyr-245 side chain against the adenine moiety, an interaction seen in the structure of G. lamblia CK in complex with AMP-PNP. Mass spectrometry coupled with trypsin digestion confirmed the selective covalent thiocarbamoylation of Cys-242 in solution. The Giardia viability studies in the metronidazole-resistant strain and the G. lamblia CK irreversible inactivation mechanism show that the thiuram compounds can circumvent the resistance mechanism that renders metronidazole ineffectiveness in drug resistance cases of giardiasis. Together, the studies suggest that G. lamblia CK is an attractive drug target for development of novel antigiardial therapies and that disulfiram, an FDA-approved drug, is a promising candidate for drug repurposing.


    Related Citations: 
    • Crystal structures of carbamate kinase from Giardia lamblia bound with citric acid and AMP-PNP.
      Lim, K.,Kulakova, L.,Galkin, A.,Herzberg, O.
      (2013) Plos One 8: e64004
    • X-ray structure and characterization of carbamate kinase from the human parasite Giardia lamblia.
      Galkin, A.,Kulakova, L.,Wu, R.,Nash, T.E.,Dunaway-Mariano, D.,Herzberg, O.
      (2010) Acta Crystallogr.,Sect.F 66: 386


    Organizational Affiliation

    From the Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland 20850.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbamate kinase
A, B, C, D
317Giardia intestinalis (strain ATCC 50803 / WB clone C6)Mutation(s): 0 
Find proteins for A8BB85 (Giardia intestinalis (strain ATCC 50803 / WB clone C6))
Go to UniProtKB:  A8BB85
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CIT
Query on CIT

Download SDF File 
Download CCD File 
A, B, C, D
CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
 Ligand Interaction
DCD
Query on DCD

Download SDF File 
Download CCD File 
A, B, C
DIETHYLCARBAMODITHIOIC ACID
C5 H11 N S2
LMBWSYZSUOEYSN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.206 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 70.297α = 90.00
b = 98.178β = 107.57
c = 102.674γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
Aimlessdata scaling
JBluIce-EPICSdata collection
PHASERphasing
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2014-01-23 
  • Released Date: 2014-02-26 
  • Deposition Author(s): Lim, K., Herzberg, O.

Revision History 

  • Version 1.0: 2014-02-26
    Type: Initial release
  • Version 1.1: 2014-03-26
    Type: Database references
  • Version 1.2: 2014-04-30
    Type: Database references
  • Version 1.3: 2017-11-22
    Type: Refinement description