1SUO

Structure of mammalian cytochrome P450 2B4 with bound 4-(4-chlorophenyl)imidazole


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.215 

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This is version 1.3 of the entry. See complete history


Literature

Structure of mammalian cytochrome P450 2B4 complexed with 4-(4-chlorophenyl)imidazole at 1.9 {angstrom} resolution: Insight into the range of P450 conformations and coordination of redox partner binding.

Scott, E.E.White, M.A.He, Y.A.Johnson, E.F.Stout, C.D.Halpert, J.R.

(2004) J Biol Chem 279: 27294-27301

  • DOI: 10.1074/jbc.M403349200
  • Primary Citation of Related Structures:  
    1SUO

  • PubMed Abstract: 
  • A 1.9-A molecular structure of the microsomal cytochrome P450 2B4 with the specific inhibitor 4-(4-chlorophenyl)imidazole (CPI) in the active site was determined by x-ray crystallography. In contrast to the previous experimentally determined 2B4 structure, this complex adopted a closed conformation similar to that observed for the mammalian 2C enzymes ...

    A 1.9-A molecular structure of the microsomal cytochrome P450 2B4 with the specific inhibitor 4-(4-chlorophenyl)imidazole (CPI) in the active site was determined by x-ray crystallography. In contrast to the previous experimentally determined 2B4 structure, this complex adopted a closed conformation similar to that observed for the mammalian 2C enzymes. The differences between the open and closed structures of 2B4 were primarily limited to the lid domain of helices F through G, helices B' and C, the N terminus of helix I, and the beta(4) region. These large-scale conformational changes were generally due to the relocation of conserved structural elements toward each other with remarkably little remodeling at the secondary structure level. For example, the F' and G' helices were maintained with a sharp turn between them but are placed to form the exterior ceiling of the active site in the CPI complex. CPI was closely surrounded by residues from substrate recognition sites 1, 4, 5, and 6 to form a small, isolated hydrophobic cavity. The switch from open to closed conformation dramatically relocated helix C to a more proximal position. As a result, heme binding interactions were altered, and the putative NADPH-cytochrome P450 reductase binding site was reformed. This suggests a structural mechanism whereby ligand-induced conformational changes may coordinate catalytic activity. Comparison of the 2B4/CPI complex with the open 2B4 structure yields insights into the dynamics involved in substrate access, tight inhibitor binding, and coordination of substrate and redox partner binding.


    Related Citations: 
    • An Open Conformation of Mammalian Cytochrome P450 2B4 at 1.6 A Resolution
      Scott, E.E., He, Y.A., Wester, M.R., White, M.A., Chin, C.C., Halpert, J.R., Johnson, E.F., Stout, C.D.
      (2003) Proc Natl Acad Sci U S A 100: 13196
    • A Truncation of 2B Subfamily Cytochromes P450 Yields Increased Expression Levels, Increased Solubility, and Decreased Aggregation While Retaining Function
      Scott, E.E., Spatzenegger, M., Halpert, J.R.
      (2001) Arch Biochem Biophys 395: 57

    Organizational Affiliation

    Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston 77555-1031, USA. eescott@ku.edu



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cytochrome P450 2B4A476Oryctolagus cuniculusMutation(s): 9 
Gene Names: CYP2B4
EC: 1.14.14.1
Membrane Entity: Yes 
UniProt
Find proteins for P00178 (Oryctolagus cuniculus)
Explore P00178 
Go to UniProtKB:  P00178
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM (Subject of Investigation/LOI)
Query on HEM

Download Ideal Coordinates CCD File 
B [auth A]PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
CPZ (Subject of Investigation/LOI)
Query on CPZ

Download Ideal Coordinates CCD File 
C [auth A]4-(4-CHLOROPHENYL)IMIDAZOLE
C9 H7 Cl N2
DVKIFCXVRCGAEE-UHFFFAOYSA-N
 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
CPZ Binding MOAD:  1SUO IC50: 40 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.239 
  • R-Value Work: 0.215 
  • Space Group: P 63 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 233.386α = 90
b = 233.386β = 90
c = 56.38γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing
CNSrefinement
CCP4data 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: 2004-07-20
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations