2B0T

Structure of Monomeric NADP Isocitrate dehydrogenase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Substrate-free structure of a monomeric NADP isocitrate dehydrogenase: An open conformation phylogenetic relationship of isocitrate dehydrogenase.

Imabayashi, F.Aich, S.Prasad, L.Delbaere, L.T.

(2006) Proteins 63: 100-112

  • DOI: 10.1002/prot.20867
  • Also Cited By: 3MBC

  • PubMed Abstract: 
  • Both monomeric and dimeric NADP+-dependent isocitrate dehydrogenase (IDH) belong to the metal-dependent beta-decarboxylating dehydrogenase family and catalyze the oxidative decarboxylation from 2R,3S-isocitrate to yield 2-oxoglutarate, CO2, and NADPH ...

    Both monomeric and dimeric NADP+-dependent isocitrate dehydrogenase (IDH) belong to the metal-dependent beta-decarboxylating dehydrogenase family and catalyze the oxidative decarboxylation from 2R,3S-isocitrate to yield 2-oxoglutarate, CO2, and NADPH. It is important to solve the structures of IDHs from various species to correlate with its function and evolutionary significance. So far, only two crystal structures of substrate/cofactor-bound (isocitrate/NADP) NADP+-dependent monomeric IDH from Azotobacter vinelandii (AvIDH) have been solved. Herein, we report for the first time the substrate/cofactor-free structure of a monomeric NADP+-dependent IDH from Corynebacterium glutamicum (CgIDH) in the presence of Mg2+. The 1.75 A structure of CgIDH-Mg2+ showed a distinct open conformation in contrast to the closed conformation of AvIDH-isocitrate/NADP+ complexes. Fluorescence studies on CgIDH in the presence of isocitrate/or NADP+ suggest the presence of low energy barrier conformers. In CgIDH, the amino acid residues corresponding to the Escherichia coli IDH phosphorylation-loop are alpha-helical compared with the more flexible random-coil region in the E. coli protein where IDH activation is controlled by phosphorylation. This more structured region supports the idea that activation of CgIDH is not controlled by phosphorylation. Monomeric NADP+-specific IDHs have been identified from about 50 different bacterial species, such as proteobacteria, actinobacteria, and planctomycetes, whereas, dimeric NADP+-dependent IDHs are diversified in both prokaryotes and eukaryotes. We have constructed a phylogenetic tree based on amino acid sequences of all bacterial monomeric NADP+-dependent IDHs and also another one with specifically chosen species which either contains both monomeric and dimeric NADP+-dependent IDHs or have monomeric NADP+-dependent, as well as NAD+-dependent IDHs. This is done to examine evolutionary relationships.


    Organizational Affiliation

    Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NADP Isocitrate dehydrogenase
A
738Corynebacterium glutamicum (strain ATCC 13032 / DSM 20300 / JCM 1318 / LMG 3730 / NCIMB 10025)Mutation(s): 0 
Gene Names: icd
EC: 1.1.1.42
Find proteins for P50216 (Corynebacterium glutamicum (strain ATCC 13032 / DSM 20300 / JCM 1318 / LMG 3730 / NCIMB 10025))
Go to UniProtKB:  P50216
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.200 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 129.046α = 90.00
b = 52.692β = 108.98
c = 124.035γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
AMoREphasing
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-01-31
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance