Crystal structure of Cytochrome P450 170A1 (CYP170A1) from Streptomyces coelicolor

Experimental Data Snapshot

  • Resolution: 2.60 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.212 

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Crystal structure of albaflavenone monooxygenase containing a moonlighting terpene synthase active site

Zhao, B.Lei, L.Vassylyev, D.G.Lin, X.Cane, D.E.Kelly, S.L.Yuan, H.Lamb, D.C.Waterman, M.R.

(2009) J Biol Chem 284: 36711-36719

  • DOI: https://doi.org/10.1074/jbc.M109.064683
  • Primary Citation of Related Structures:  
    3DBG, 3EL3

  • PubMed Abstract: 

    Albaflavenone synthase (CYP170A1) is a monooxygenase catalyzing the final two steps in the biosynthesis of this antibiotic in the soil bacterium, Streptomyces coelicolor A3(2). Interestingly, CYP170A1 shows no stereo selection forming equal amounts of two albaflavenol epimers, each of which is oxidized in turn to albaflavenone. To explore the structural basis of the reaction mechanism, we have studied the crystal structures of both ligand-free CYP170A1 (2.6 A) and complex of endogenous substrate (epi-isozizaene) with CYP170A1 (3.3 A). The structure of the complex suggests that the proximal epi-isozizaene molecules may bind to the heme iron in two orientations. In addition, much to our surprise, we have found that albaflavenone synthase also has a second, completely distinct catalytic activity corresponding to the synthesis of farnesene isomers from farnesyl diphosphate. Within the cytochrome P450 alpha-helical domain both the primary sequence and x-ray structure indicate the presence of a novel terpene synthase active site that is moonlighting on the P450 structure. This includes signature sequences for divalent cation binding and an alpha-helical barrel. This barrel is unusual because it consists of only four helices rather than six found in all other terpene synthases. Mutagenesis establishes that this barrel is essential for the terpene synthase activity of CYP170A1 but not for the monooxygenase activity. This is the first bifunctional P450 discovered to have another active site moonlighting on it and the first time a terpene synthase active site is found moonlighting on another protein.

  • Organizational Affiliation

    Department of Biochemistry, Center for Structural Biology, and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146. Electronic address: bin.zhao@vanderbilt.edu.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Putative cytochrome P450
A, B
467Streptomyces coelicolor A3(2)Mutation(s): 0 
Find proteins for Q9K498 (Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145))
Explore Q9K498 
Go to UniProtKB:  Q9K498
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9K498
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: 2.60 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.212 
  • Space Group: P 63
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 103.596α = 90
b = 103.596β = 90
c = 140.861γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data 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: 2009-06-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2024-02-21
    Changes: Data collection, Database references, Derived calculations