2HUO

Crystal structure of mouse myo-inositol oxygenase in complex with substrate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of a substrate complex of myo-inositol oxygenase, a di-iron oxygenase with a key role in inositol metabolism.

Brown, P.M.Caradoc-Davies, T.T.Dickson, J.M.Cooper, G.J.Loomes, K.M.Baker, E.N.

(2006) Proc.Natl.Acad.Sci.Usa 103: 15032-15037

  • DOI: 10.1073/pnas.0605143103
  • Also Cited By: 3BXD

  • PubMed Abstract: 
  • Altered metabolism of the inositol sugars myo-inositol (MI) and d-chiro-inositol is implicated in diabetic complications. In animals, catabolism of MI and D-chiro-inositol depends on the enzyme MI oxygenase (MIOX), which catalyzes the first committed ...

    Altered metabolism of the inositol sugars myo-inositol (MI) and d-chiro-inositol is implicated in diabetic complications. In animals, catabolism of MI and D-chiro-inositol depends on the enzyme MI oxygenase (MIOX), which catalyzes the first committed step of the glucuronate-xylulose pathway, and is found almost exclusively in the kidneys. The crystal structure of MIOX, in complex with MI, has been determined by multiwavelength anomalous diffraction methods and refined at 2.0-A resolution (R=0.206, Rfree=0.253). The structure reveals a monomeric, single-domain protein with a mostly helical fold that is distantly related to the diverse HD domain superfamily. Five helices form the structural core and provide six ligands (four His and two Asp) for the di-iron center, in which the two iron atoms are bridged by a putative hydroxide ion and one of the Asp ligands, Asp-124. A key loop forms a lid over the MI substrate, which is coordinated in bidentate mode to one iron atom. It is proposed that this mode of iron coordination, and interaction with a key Lys residue, activate MI for bond cleavage. The structure also reveals the basis of substrate specificity and suggests routes for the development of specific MIOX inhibitors.


    Organizational Affiliation

    Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, and Department of Chemistry, University of Auckland, Auckland 1142, New Zealand.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Inositol oxygenase
A
289Mus musculusMutation(s): 0 
Gene Names: Miox (Aldrl6, Rsor)
EC: 1.13.99.1
Find proteins for Q9QXN5 (Mus musculus)
Go to UniProtKB:  Q9QXN5
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMT
Query on FMT

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Download CCD File 
A
FORMIC ACID
C H2 O2
BDAGIHXWWSANSR-UHFFFAOYSA-N
 Ligand Interaction
INS
Query on INS

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Download CCD File 
A
1,2,3,4,5,6-HEXAHYDROXY-CYCLOHEXANE
MYO-INOSITOL
C6 H12 O6
CDAISMWEOUEBRE-GPIVLXJGSA-N
 Ligand Interaction
OH
Query on OH

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Download CCD File 
A
HYDROXIDE ION
H O
XLYOFNOQVPJJNP-UHFFFAOYSA-M
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.204 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 44.602α = 90.00
b = 77.202β = 90.00
c = 85.397γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
CCP4data scaling
SHARPphasing
MOSFLMdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-09-26
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Refinement description, Version format compliance