1PB3

Sites of binding and orientation in a four location model for protein stereospecificity.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Sites of Binding and Orientation in a Four-Location Model for Protein Stereospecificity.

Mesecar, A.D.Koshland Jr., D.E.

(2000) IUBMB Life 49: 457-466

  • DOI: 10.1080/152165400410326

  • PubMed Abstract: 
  • The stereospecificity of the enzyme isocitrate dehydrogenase was examined by steady-state kinetics and x-ray crystallography. The enzyme has the intriguing property that the apoenzyme in the absence of divalent metal showed a selectivity for the inac ...

    The stereospecificity of the enzyme isocitrate dehydrogenase was examined by steady-state kinetics and x-ray crystallography. The enzyme has the intriguing property that the apoenzyme in the absence of divalent metal showed a selectivity for the inactive l-enantiomer of the substrate isocitrate, whereas the enzyme containing magnesium showed selectivity for the physiologically active d-enantiomer. The hydrogen atom on the C2 carbon that is transferred during the reaction was, in both the d- and l-isocitrate complexes, in an orientation very close to that expected for delivery of a hydride ion to the cosubstrate NADP+. The beta-carboxylate that is eliminated as a CO2 molecule during the reaction occupied the same site on the protein in both the d- and l-isocitrate complexes. In addition, the C3 carbon was in the same protein site in both the d- and l-enantiomers. Only the fourth group, the OH atom, was in a very different position in the apo enzyme and in the metal-containing complexes. A four-location model is necessary to explain the enantiomeric specificity of IDH in contrast to the conventional three-point attachment model. The thermodynamic and kinetic ramifications of this model are explored.


    Related Citations: 
    • Structural Biology: A New Model for Protein Stereospecificity.
      Mesecar, A.D.,Koshland Jr., D.E.
      (2000) Nature 403: 614


    Organizational Affiliation

    Center for Pharmaceutical Biotechnology and the Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 60607, USA. mesecar@uic.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Isocitrate dehydrogenase [NADP]
A
416Escherichia coli (strain K12)Gene Names: icd (icdA, icdE)
EC: 1.1.1.42
Find proteins for P08200 (Escherichia coli (strain K12))
Go to UniProtKB:  P08200
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.194 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 103.669α = 90.00
b = 103.669β = 90.00
c = 150.124γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
SCALEPACKdata scaling
DENZOdata reduction
EPMRphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-06-17
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2018-01-31
    Type: Experimental preparation