1OLM

Supernatant Protein Factor in Complex with RRR-alpha-Tocopherylquinone: A Link between Oxidized Vitamin E and Cholesterol Biosynthesis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Supernatant Protein Factor in Complex with Rrr-Alpha-Tocopherylquinone: A Link between Oxidized Vitamin E and Cholesterol Biosynthesis

Stocker, A.Baumann, U.

(2003) J.Mol.Biol. 332: 759


  • PubMed Abstract: 
  • The vast majority of monomeric lipid transport in nature is performed by lipid-specific protein carriers. This class of proteins can enclose cognate lipid molecules in a hydrophobic cavity and transport them across the aqueous environment. Supernatan ...

    The vast majority of monomeric lipid transport in nature is performed by lipid-specific protein carriers. This class of proteins can enclose cognate lipid molecules in a hydrophobic cavity and transport them across the aqueous environment. Supernatant protein factor (SPF) is an enigmatic representative of monomeric lipid transporters belonging to the SEC14 family. SPF stimulates squalene epoxidation, a downstream step of the cholesterol biosynthetic pathway, by an unknown mechanism. Here, we present the three-dimensional crystal structure of human SPF in complex with RRR-alpha-tocopherylquinone, the major physiological oxidation product of RRR-alpha-tocopherol, at a resolution of 1.95A. The structure of the complex reveals how SPF sequesters RRR-alpha-tocopherylquinone (RRR-alpha-TQ) in its protein body and permits a comparison with the recently solved structure of human alpha-tocopherol transfer protein (alpha-TTP) in complex with RRR-alpha-tocopherol. Recent findings have shown that RRR-alpha-TQ is reduced in vivo to RRR-alpha-TQH(2), the latter has been suggested to protect low-density lipoprotein (LDL) particles from oxidation. Hence, the antioxidant function of the redox couple RRR-alpha-TQ/RRR-alpha-TQH(2) in blocking LDL oxidation may reduce cellular cholesterol uptake and thus explain how SPF upregulates cholesterol synthesis.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Berne, 3012 Bern, Switzerland. achim.stocker@ibc.unibe.ch




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SEC14-LIKE PROTEIN 2
A, C
403Homo sapiensGene Names: SEC14L2 (C22orf6, KIAA1186, KIAA1658)
Find proteins for O76054 (Homo sapiens)
Go to Gene View: SEC14L2
Go to UniProtKB:  O76054
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
SEC14-LIKE PROTEIN 2
E
403Homo sapiensGene Names: SEC14L2 (C22orf6, KIAA1186, KIAA1658)
Find proteins for O76054 (Homo sapiens)
Go to Gene View: SEC14L2
Go to UniProtKB:  O76054
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
VTQ
Query on VTQ

Download SDF File 
Download CCD File 
A, C, E
RRR-ALPHA-TOCOPHERYLQUINONE
C29 H50 O3
LTVDFSLWFKLJDQ-IEOSBIPESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.180 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 60.856α = 116.20
b = 84.621β = 102.64
c = 87.452γ = 100.24
Software Package:
Software NamePurpose
XDSdata scaling
XSCALEdata scaling
REFMACrefinement
CNSphasing
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-12
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance