1A05

CRYSTAL STRUCTURE OF THE COMPLEX OF 3-ISOPROPYLMALATE DEHYDROGENASE FROM THIOBACILLUS FERROOXIDANS WITH 3-ISOPROPYLMALATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 
    0.275 (Depositor), 0.250 (DCC) 
  • R-Value Work: 
    0.198 (Depositor), 0.190 (DCC) 
  • R-Value Observed: 
    0.198 (Depositor) 

Starting Model: experimental
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Ligand Structure Quality Assessment 

Created with Raphaël 2.3.0Worse 01 BetterLigand structure goodness of fit to experimental dataBest fitted IPMClick on this verticalbar to view details

This is version 1.4 of the entry. See complete history


Literature

Structure of 3-isopropylmalate dehydrogenase in complex with 3-isopropylmalate at 2.0 A resolution: the role of Glu88 in the unique substrate-recognition mechanism.

Imada, K.Inagaki, K.Matsunami, H.Kawaguchi, H.Tanaka, H.Tanaka, N.Namba, K.

(1998) Structure 6: 971-982

  • DOI: https://doi.org/10.1016/s0969-2126(98)00099-9
  • Primary Citation of Related Structures:  
    1A05

  • PubMed Abstract: 

    3-Isopropylmalate dehydrogenase (IPMDH) and isocitrate dehydrogenase (ICDH) belong to a unique family of bifunctional decarboxylating dehydrogenases. Although the ICDH dimer catalyzes its reaction under a closed conformation, known structures of the IPMDH dimer (without substrate) adopt a fully open or a partially closed form. Considering the similarity in the catalytic mechanism, the IPMDH dimer must be in a fully closed conformation during the reaction. A large conformational change should therefore occur upon substrate binding. We have determined the crystal structure of IPMDH from Thiobacillus ferrooxidans (Tf) complexed with 3-isopropylmalate (IPM) at 2.0 A resolution by the molecular replacement method. The structure shows a fully closed conformation and the substrate-binding site is quite similar to that of ICDH except for a region around the gamma-isopropyl group. The gamma group is recognized by a unique hydrophobic pocket, which includes Glu88, Leu91 and Leu92 from subunit 1 and Val193' from subunit 2. A large movement of domain 1 is induced by substrate binding, which results in the formation of the hydrophobic pocket for the gamma-isopropyl moiety of IPM. A glutamic acid in domain 1, Glu88, participates in the formation of the hydrophobic pocket. The C beta and C gamma atoms of Glu88 interact with the gamma-isopropyl moiety of IPM and are central to the recognition of substrate. The acidic tip of Glu88 is likely to interact with the nicotinamide mononucleotide (NMN) ribose of NAD+ in the ternary complex. This structure clearly explains the substrate specificity of IPMDH.


  • Organizational Affiliation

    International Institute for Advanced Research, Matsushita Electric Industrial Co., Ltd., Seika, Japan. kimada@npn.jst.go.jp


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
3-ISOPROPYLMALATE DEHYDROGENASE
A, B
358Acidithiobacillus ferrooxidansMutation(s): 0 
Gene Names: LEUB
EC: 1.1.1.85
UniProt
Find proteins for Q56268 (Acidithiobacillus ferrooxidans)
Explore Q56268 
Go to UniProtKB:  Q56268
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ56268
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free:  0.275 (Depositor), 0.250 (DCC) 
  • R-Value Work:  0.198 (Depositor), 0.190 (DCC) 
  • R-Value Observed: 0.198 (Depositor) 
Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 56.54α = 90
b = 114.24β = 90
c = 130.89γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
PROCESSdata reduction
PROCESSdata scaling
X-PLORphasing

Structure Validation

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Ligand Structure Quality Assessment 

Created with Raphaël 2.3.0Worse 01 BetterLigand structure goodness of fit to experimental dataBest fitted IPMClick on this verticalbar to view details

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-06-17
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-02
    Changes: Database references, Derived calculations, Other, Refinement description
  • Version 1.4: 2024-05-22
    Changes: Data collection