2GMH

Structure of Porcine Electron Transfer Flavoprotein-Ubiquinone Oxidoreductase in Complexed with Ubiquinone


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of electron transfer flavoprotein-ubiquinone oxidoreductase and electron transfer to the mitochondrial ubiquinone pool.

Zhang, J.Frerman, F.E.Kim, J.J.

(2006) Proc.Natl.Acad.Sci.Usa 103: 16212-16217

  • DOI: 10.1073/pnas.0604567103
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a 4Fe4S flavoprotein located in the inner mitochondrial membrane. It catalyzes ubiquinone (UQ) reduction by ETF, linking oxidation of fatty acids and some amino acids to the mitocho ...

    Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a 4Fe4S flavoprotein located in the inner mitochondrial membrane. It catalyzes ubiquinone (UQ) reduction by ETF, linking oxidation of fatty acids and some amino acids to the mitochondrial respiratory chain. Deficiencies in ETF or ETF-QO result in multiple acyl-CoA dehydrogenase deficiency, a human metabolic disease. Crystal structures of ETF-QO with and without bound UQ were determined, and they are essentially identical. The molecule forms a single structural domain. Three functional regions bind FAD, the 4Fe4S cluster, and UQ and are closely packed and share structural elements, resulting in no discrete structural domains. The UQ-binding pocket consists mainly of hydrophobic residues, and UQ binding differs from that of other UQ-binding proteins. ETF-QO is a monotopic integral membrane protein. The putative membrane-binding surface contains an alpha-helix and a beta-hairpin, forming a hydrophobic plateau. The UQ-flavin distance (8.5 A) is shorter than the UQ-cluster distance (18.8 A), and the very similar redox potentials of FAD and the cluster strongly suggest that the flavin, not the cluster, transfers electrons to UQ. Two possible electron transfer paths can be envisioned. First, electrons from the ETF flavin semiquinone may enter the ETF-QO flavin one by one, followed by rapid equilibration with the cluster. Alternatively, electrons may enter via the cluster, followed by equilibration between centers. In both cases, when ETF-QO is reduced to a two-electron reduced state (one electron at each redox center), the enzyme is primed to reduce UQ to ubiquinol via FAD.


    Organizational Affiliation

    Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Electron transfer flavoprotein-ubiquinone oxidoreductase
A, B
584Sus scrofaMutation(s): 0 
Gene Names: ETFDH
EC: 1.5.5.1
Membrane protein
mpstruct
Group: 
MONOTOPIC MEMBRANE PROTEINS
Sub Group: 
Oxidoreductases (Monotopic)
Protein: 
Electron Transfer Flavoprotein-ubiquinone oxidoreductase (ETF-QO) with bound UQ
Find proteins for P55931 (Sus scrofa)
Go to Gene View: ETFDH
Go to UniProtKB:  P55931
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SF4
Query on SF4

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A, B
IRON/SULFUR CLUSTER
Fe4 S4
LJBDFODJNLIPKO-VKOJMFJBAC
 Ligand Interaction
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
UQ5
Query on UQ5

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A, B
2,3-DIMETHOXY-5-METHYL-6-(3,11,15,19-TETRAMETHYL-EICOSA-2,6,10,14,18-PENTAENYL)-[1,4]BENZOQUINONE
C34 H50 O4
NYFAQDMDAFCWPU-UVCHAVPFSA-N
 Ligand Interaction
FAD
Query on FAD

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A, B
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
BHG
Query on BHG

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A, B
2-HEXYLOXY-6-HYDROXYMETHYL-TETRAHYDRO-PYRAN-3,4,5-TRIOL
C12 H24 O6
JVAZJLFFSJARQM-YBXAARCKSA-N
 Ligand Interaction
EDO
Query on EDO

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A, B
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.221 
  • Space Group: P 4 21 2
Unit Cell:
Length (Å)Angle (°)
a = 154.322α = 90.00
b = 154.322β = 90.00
c = 128.536γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
X-PLORphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-10-17
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance