2Q9F

Crystal structure of human cytochrome P450 46A1 in complex with cholesterol-3-sulphate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.183 

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This is version 1.1 of the entry. See complete history


Literature

Crystal structures of substrate-bound and substrate-free cytochrome P450 46A1, the principal cholesterol hydroxylase in the brain.

Mast, N.White, M.A.Bjorkhem, I.Johnson, E.F.Stout, C.D.Pikuleva, I.A.

(2008) Proc Natl Acad Sci U S A 105: 9546-9551

  • DOI: 10.1073/pnas.0803717105
  • Primary Citation of Related Structures:  
    2Q9F, 2Q9G

  • PubMed Abstract: 
  • By converting cholesterol to 24S-hydroxycholesterol, cytochrome P450 46A1 (CYP46A1) initiates the major pathway for cholesterol removal from the brain. Two crystal structures of CYP46A1 were determined. First is the 1.9-A structure of CYP46A1 complexed with a high-affinity substrate cholesterol 3-sulfate (CH-3S) ...

    By converting cholesterol to 24S-hydroxycholesterol, cytochrome P450 46A1 (CYP46A1) initiates the major pathway for cholesterol removal from the brain. Two crystal structures of CYP46A1 were determined. First is the 1.9-A structure of CYP46A1 complexed with a high-affinity substrate cholesterol 3-sulfate (CH-3S). The second structure is that of the substrate-free CYP46A1 at 2.4-A resolution. CH-3S is bound in the productive orientation and occupies the entire length of the banana-shaped hydrophobic active-site cavity. A unique helix B'-C loop insertion (residues 116-120) contributes to positioning cholesterol for oxygenation catalyzed by CYP46A1. A comparison with the substrate-free structure reveals substantial substrate-induced conformational changes in CYP46A1 and suggests that structurally distinct compounds could bind in the enzyme active site. In vitro assays were performed to characterize the effect of different therapeutic agents on cholesterol hydroxylase activity of purified full-length recombinant CYP46A1, and several strong inhibitors and modest coactivators of CYP46A1 were identified. Structural and biochemical data provide evidence that CYP46A1 activity could be altered by exposure to some therapeutic drugs and potentially other xenobiotics.


    Related Citations: 
    • Use of complementary cation and anion heavy-atom salt derivatives to solve the structure of cytochrome P450 46A1.
      White, M.A., Mast, N., Bjorkhem, I., Johnson, E.F., Stout, C.D., Pikuleva, I.A.
      (2008) Acta Crystallogr D Biol Crystallogr 64: 487

    Organizational Affiliation

    Department of Pharmacology and Toxicology, The Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome P450 46A1A456Homo sapiensMutation(s): 0 
Gene Names: CYP46A1CYP46
EC: 1.14.13.98 (PDB Primary Data), 1.14.14.25 (UniProt)
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for Q9Y6A2 (Homo sapiens)
Explore Q9Y6A2 
Go to UniProtKB:  Q9Y6A2
PHAROS:  Q9Y6A2
Protein Feature View
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  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
C3S Binding MOAD:  2Q9F Kd: 7 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.183 
  • Space Group: I 41 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 121.85α = 90
b = 121.85β = 90
c = 144.03γ = 90
Software Package:
Software NamePurpose
SOLVEphasing
CNSrefinement
Blu-Icedata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-06-17
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance