1MEI

Inosine Monophosphate Dehydrogenase (IMPDH) From Tritrichomonas Foetus with XMP and mycophenolic acid bound


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.227 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal Structures of Tritrichomonas foetus Inosine Monophosphate Dehydrogenase in Complex with Substrate, Cofactor and Analogs: A Structural Basis for the Random-in Ordered-out Kinetic Mechanism

Prosise, G.L.Luecke, H.

(2003) J.Mol.Biol. 326: 517-527

  • Primary Citation of Related Structures:  1ME9, 1MEH, 1MEW

  • PubMed Abstract: 
  • The enzyme inosine monophosphate dehydrogenase (IMPDH) is responsible for the rate-limiting step in guanine nucleotide biosynthesis. Because it is up-regulated in rapidly proliferating cells, human type II IMPDH is actively targeted for immunosuppres ...

    The enzyme inosine monophosphate dehydrogenase (IMPDH) is responsible for the rate-limiting step in guanine nucleotide biosynthesis. Because it is up-regulated in rapidly proliferating cells, human type II IMPDH is actively targeted for immunosuppressive, anticancer, and antiviral chemotherapy. The enzyme employs a random-in ordered-out kinetic mechanism where substrate or cofactor can bind first but product is only released after the cofactor leaves. Due to structural and kinetic differences between mammalian and microbial enzymes, most drugs that are successful in the inhibition of mammalian IMPDH are far less effective against the microbial forms of the enzyme. It is possible that with greater knowledge of the structural mechanism of the microbial enzymes, an effective and selective inhibitor of microbial IMPDH will be developed for use as a drug against multi-drug resistant bacteria and protists. The high-resolution crystal structures of four different complexes of IMPDH from the protozoan parasite Tritrichomonas foetus have been solved: with its substrate IMP, IMP and the inhibitor mycophenolic acid (MPA), the product XMP with MPA, and XMP with the cofactor NAD(+). In addition, a potassium ion has been located at the dimer interface. A structural model for the kinetic mechanism is proposed.


    Organizational Affiliation

    Department of Molecular Biology and Biochemistry University of California, Irvine, CA 92697-3900 USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
INOSINE-5'-MONOPHOSPHATE DEHYDROGENASE
A
503Tritrichomonas foetusGene Names: IMPDH
EC: 1.1.1.205
Find proteins for P50097 (Tritrichomonas foetus)
Go to UniProtKB:  P50097
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
XMP
Query on XMP

Download SDF File 
Download CCD File 
A
XANTHOSINE-5'-MONOPHOSPHATE
5-MONOPHOSPHATE-9-BETA-D-RIBOFURANOSYL XANTHINE
C10 H14 N4 O9 P
DCTLYFZHFGENCW-UUOKFMHZSA-O
 Ligand Interaction
MOA
Query on MOA

Download SDF File 
Download CCD File 
A
MYCOPHENOLIC ACID
6-(1,3-DIHYDRO-7-HYDROXY-5-METHOXY-4-METHYL-1-OXOISOBENZOFURAN-6-YL)-4-METHYL-4-HEXANOIC ACID
C17 H20 O6
HPNSFSBZBAHARI-RUDMXATFSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.227 
  • Space Group: P 4 3 2
Unit Cell:
Length (Å)Angle (°)
a = 155.070α = 90.00
b = 155.070β = 90.00
c = 155.070γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
CNSphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-08-12
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance