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 
  • R-Value Observed: 0.181 

wwPDB Validation   3D Report Full Report


This is version 1.3 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

  • DOI: https://doi.org/10.1016/s0022-2836(03)00924-0
  • Primary Citation of Related Structures:  
    1OLM

  • 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. 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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
SEC14-LIKE PROTEIN 2A,
B [auth C]
403Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for O76054 (Homo sapiens)
Explore O76054 
Go to UniProtKB:  O76054
PHAROS:  O76054
GTEx:  ENSG00000100003 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO76054
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
SEC14-LIKE PROTEIN 2C [auth E]403Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for O76054 (Homo sapiens)
Explore O76054 
Go to UniProtKB:  O76054
PHAROS:  O76054
GTEx:  ENSG00000100003 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO76054
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.856α = 116.2
b = 84.621β = 102.64
c = 87.452γ = 100.24
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XDSdata scaling
XSCALEdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-08-12
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-05-08
    Changes: Data collection, Database references