1AI2

ISOCITRATE DEHYDROGENASE COMPLEXED WITH ISOCITRATE, NADP+, AND CALCIUM (FLASH-COOLED)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.191 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history. 


Literature

Orbital steering in the catalytic power of enzymes: small structural changes with large catalytic consequences.

Mesecar, A.D., Stoddard, B.L., Koshland Jr., D.E.

(1997) Science 277: 202-206

  • DOI: 10.1126/science.277.5323.202
  • Primary Citation of Related Structures:  
    1AI2, 1AI3

  • PubMed Abstract: 

    • Small structural perturbations in the enzyme isocitrate dehydrogenase (IDH) were made in order to evaluate the contribution of precise substrate alignment to the catalytic power of an enzyme. The reaction trajectory of IDH was modified (i) after the adenine moiety of nicotinamide adenine dinucleotide phosphate was changed to hypoxanthine (the 6-amino was changed to 6-hydroxyl), and (ii) by replacing Mg2+, which has six coordinating ligands, with Ca2+, which has eight coordinating ligands ...

    Small structural perturbations in the enzyme isocitrate dehydrogenase (IDH) were made in order to evaluate the contribution of precise substrate alignment to the catalytic power of an enzyme. The reaction trajectory of IDH was modified (i) after the adenine moiety of nicotinamide adenine dinucleotide phosphate was changed to hypoxanthine (the 6-amino was changed to 6-hydroxyl), and (ii) by replacing Mg2+, which has six coordinating ligands, with Ca2+, which has eight coordinating ligands. Both changes make large (10(-3) to 10(-5)) changes in the reaction velocity but only small changes in the orientation of the substrates (both distance and angle) as revealed by cryocrystallographic trapping of active IDH complexes. The results provide evidence that orbital overlap produced by optimal orientation of reacting orbitals plays a major quantitative role in the catalytic power of enzymes.

    Related Citations: 
    • Determinants of Cofactor Specificity in Isocitrate Dehydrogenase: Structure of an Engineered Nadp+--> Nad+ Specificity-Reversal Mutant
      Hurley, J.H., Chen, R., Dean, A.M.
      (1996) Biochemistry 35: 5670
    • Structure of Isocitrate Dehydrogenase with Isocitrate, Nicotinamide Adenine Dinucleotide Phosphate, and Calcium at 2.5-A Resolution: A Pseudo-Michaelis Ternary Complex
      Stoddard, B.L., Dean, A., Koshland Junior, D.E.
      (1993) Biochemistry 32: 9310
    Organizational Affiliation: 

    Department of Molecular and Cell Biology, Stanley Hall, University of California, Berkeley, CA 94720, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ISOCITRATE DEHYDROGENASEA416Escherichia coliMutation(s): 0 
EC: 1.1.1.42
UniProt
Find proteins for P08200 (Escherichia coli (strain K12))
Explore P08200 
Go to UniProtKB:  P08200
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08200
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAP
Query on NAP
Download Ideal Coordinates CCD File 
B [auth A]NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H28 N7 O17 P3
XJLXINKUBYWONI-NNYOXOHSSA-N		 Ligand Interaction
ICA
Query on ICA
Download Ideal Coordinates CCD File 
C [auth A]ISOCITRATE CALCIUM COMPLEX
C6 H7 Ca O7
AHEGTOWQUJMCIO-MASXSRPFDD		 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
NAP Binding MOAD:  1AI2 Ki: 2700 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.191 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 102.3α = 90
b = 102.3β = 90
c = 150.5γ = 90
Software Package:
Software NamePurpose
AMoREphasing
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-10-15
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance