1ZHZ

Structure of yeast oxysterol binding protein Osh4 in complex with ergosterol


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.207 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Structural mechanism for sterol sensing and transport by OSBP-related proteins

Im, Y.J.Raychaudhuri, S.Prinz, W.A.Hurley, J.H.

(2005) Nature 437: 154-158

  • DOI: https://doi.org/10.1038/nature03923
  • Primary Citation of Related Structures:  
    1ZHT, 1ZHW, 1ZHX, 1ZHY, 1ZHZ, 1ZI7

  • PubMed Abstract: 

    The oxysterol-binding-protein (OSBP)-related proteins (ORPs) are conserved from yeast to humans, and are implicated in the regulation of sterol homeostasis and in signal transduction pathways. Here we report the structure of the full-length yeast ORP Osh4 (also known as Kes1) at 1.5-1.9 A resolution in complexes with ergosterol, cholesterol, and 7-, 20- and 25-hydroxycholesterol. We find that a single sterol molecule binds within a hydrophobic tunnel in a manner consistent with a transport function for ORPs. The entrance is blocked by a flexible amino-terminal lid and surrounded by basic residues that are critical for Osh4 function. The structure of the open state of a lid-truncated form of Osh4 was determined at 2.5 A resolution. Structural analysis and limited proteolysis show that sterol binding closes the lid and stabilizes a conformation favouring transport across aqueous barriers and signal transmission. The structure of Osh4 in the absence of ligand exposes potential phospholipid-binding sites that are positioned for membrane docking and sterol exchange. On the basis of these observations, we propose a model in which sterol and membrane binding promote reciprocal conformational changes that facilitate a sterol transfer and signalling cycle.


  • Organizational Affiliation

    Laboratory of Molecular Biology, National Institutes of Health, US Department of Health and Human Services, Bethesda, Maryland 20892, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
KES1 protein438Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: OSH4
UniProt
Find proteins for P35844 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P35844 
Go to UniProtKB:  P35844
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP35844
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.207 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 82.033α = 90
b = 94.557β = 96.38
c = 65.264γ = 90
Software Package:
Software NamePurpose
CNSrefinement
HKL-2000data reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-09-06
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description