8SS0

Human sterol 14 alpha-demethylase (CYP51) in complex with the reaction intermediate 14 alpha-aldehyde dihydrolanosterol


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Oxygen-18 Labeling Reveals a Mixed Fe-O Mechanism in the Last Step of Cytochrome P450 51 Sterol 14 alpha-Demethylation.

McCarty, K.D.Tateishi, Y.Hargrove, T.Y.Lepesheva, G.I.Guengerich, F.P.

(2024) Angew Chem Int Ed Engl 63: e202317711-e202317711

  • DOI: https://doi.org/10.1002/anie.202317711
  • Primary Citation of Related Structures:  
    8SS0

  • PubMed Abstract: 

    The 14α-demethylation step is critical in eukaryotic sterol biosynthesis, catalyzed by cytochrome P450 (P450) Family 51 enzymes, for example, with lanosterol in mammals. This conserved three-step reaction terminates in a C-C cleavage step that generates formic acid, the nature of which has been controversial. Proposed mechanisms involve roles of P450 Compound 0 (ferric peroxide anion, FeO 2 - ) or Compound I (perferryl oxygen, FeO 3+ ) reacting with either the aldehyde or its hydrate, respectively. Analysis of 18 O incorporation into formic acid from 18 O 2 provides a means of distinguishing the two mechanisms. Human P450 51A1 incorporated 88 % 18 O (one atom) into formic acid, consistent with a major but not exclusive FeO 2 - mechanism. Two P450 51 orthologs from amoeba and yeast showed similar results, while two orthologs from pathogenic trypanosomes showed roughly equal contributions of both mechanisms. An X-ray crystal structure of the human enzyme showed the aldehyde oxygen atom 3.5 Å away from the heme iron atom. Experiments with human P450 51A1 and H 2 18 O yielded primarily one 18 O atom but 14 % of the formic acid product with two 18 O atoms, indicative of a minor contribution of a Compound I mechanism. LC-MS evidence for a Compound 0-derived Baeyer-Villiger reaction product (a 14α-formyl ester) was also found.


  • Organizational Affiliation

    Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Lanosterol 14-alpha demethylase
A, B
458Homo sapiensMutation(s): 2 
Gene Names: CYP51A1CYP51
EC: 1.14.14.154
UniProt & NIH Common Fund Data Resources
Find proteins for Q16850 (Homo sapiens)
Explore Q16850 
Go to UniProtKB:  Q16850
PHAROS:  Q16850
GTEx:  ENSG00000001630 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ16850
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 
  • Space Group: P 62 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 145.803α = 90
b = 145.803β = 90
c = 261.161γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM067871

Revision History  (Full details and data files)

  • Version 1.0: 2024-01-17
    Type: Initial release
  • Version 1.1: 2024-01-24
    Changes: Database references
  • Version 1.2: 2024-03-06
    Changes: Database references