Crystal Structure of Phe393His Cytochrome P450 BM3

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.179 

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This is version 1.5 of the entry. See complete history


Structural and spectroscopic analysis of the F393H mutant of flavocytochrome P450 BM3.

Ost, T.W.Munro, A.W.Mowat, C.G.Taylor, P.R.Pesseguiero, A.Fulco, A.J.Cho, A.K.Cheesman, M.A.Walkinshaw, M.D.Chapman, S.K.

(2001) Biochemistry 40: 13430-13438

  • DOI: https://doi.org/10.1021/bi010717e
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    In the preceding paper in this issue [Ost, T. W. B., Miles, C. S., Munro, A. W., Murdoch, J., Reid, G. A., and Chapman, S. K. (2001) Biochemistry 40, 13421-13429], we have established that the primary role of the phylogenetically conserved phenylalanine in flavocytochrome P450 BM3 (F393) is to control the thermodynamic properties of the heme iron, so as to optimize electron-transfer both to the iron (from the flavin redox partner) and onto molecular oxygen. In this paper, we report a detailed study of the F393H mutant enzyme, designed to probe the structural, spectroscopic, and metabolic profile of the enzyme in an attempt to identify the factors responsible for causing the changes. The heme domain structure of the F393H mutant has been solved to 2.0 A resolution and demonstrates that the histidine replaces the phenylalanine in almost exactly the same conformation. A solvent water molecule is hydrogen bonded to the histidine, but there appears to be little other gross alteration in the environment of the heme. The F393H mutant displays an identical ferric EPR spectrum to wild-type, implying that the degree of splitting of the iron d orbitals is unaffected by the substitution, however, the overall energy of the d-orbitals have changed relative to each other. Magnetic CD studies show that the near-IR transition, diagnostic of heme ligation state, is red-shifted by 40 nm in F393H relative to wild-type P450 BM3, probably reflecting alteration in the strength of the iron-cysteinate bond. Studies of the catalytic turnover of fatty acid (myristate) confirms NADPH oxidation is tightly coupled to fatty acid oxidation in F393H, with a product profile very similar to wild-type. The results indicate that gross conformational changes do not account for the perturbations in the electronic features of the P450 BM3 heme system and that the structural environment on the proximal side of the P450 heme must be conformationally conserved in order to optimize catalytic function.

  • Organizational Affiliation

    Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK. skc03@holyrood.ed.ac.uk

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
455Priestia megateriumMutation(s): 1 
Gene Names: CYP102A1
Find proteins for P14779 (Priestia megaterium (strain ATCC 14581 / DSM 32 / CCUG 1817 / JCM 2506 / NBRC 15308 / NCIMB 9376 / NCTC 10342 / NRRL B-14308 / VKM B-512 / Ford 19))
Explore P14779 
Go to UniProtKB:  P14779
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP14779
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on HEM

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C34 H32 Fe N4 O4
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.179 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.842α = 90
b = 153.102β = 94.67
c = 61.479γ = 90
Software Package:
Software NamePurpose
MAR345data collection
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-11-23
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.5: 2023-08-16
    Changes: Data collection, Refinement description