Functional and Structural Characterization of a Cationdependent O-Methyltransferase from the Cyanobacterium Synechocystis Sp. Strain PCC 6803

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.152 
  • R-Value Observed: 0.156 

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Functional and Structural Characterization of a Cation-dependent O-Methyltransferase from the Cyanobacterium Synechocystis sp. Strain PCC 6803

Kopycki, J.G.Stubbs, M.T.Brandt, W.Hagemann, M.Porzel, A.Schmidt, J.Schliemann, W.Zenk, M.H.Vogt, T.

(2008) J Biol Chem 283: 20888-20896

  • DOI: https://doi.org/10.1074/jbc.M801943200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The coding sequence of the cyanobacterium Synechocystis sp. strain PCC 6803 slr0095 gene was cloned and functionally expressed in Escherichia coli. The corresponding enzyme was classified as a cation- and S-adenosyl-l-methionine-dependent O-methyltransferase (SynOMT), consistent with considerable amino acid sequence identities to eukaryotic O-methyltransferases (OMTs). The substrate specificity of SynOMT was similar with those of plant and mammalian CCoAOMT-like proteins accepting a variety of hydroxycinnamic acids and flavonoids as substrates. In contrast to the known mammalian and plant enzymes, which exclusively methylate the meta-hydroxyl position of aromatic di- and trihydroxy systems, Syn-OMT also methylates the para-position of hydroxycinnamic acids like 5-hydroxyferulic and 3,4,5-trihydroxycinnamic acid, resulting in the formation of novel compounds. The x-ray structure of SynOMT indicates that the active site allows for two alternative orientations of the hydroxylated substrates in comparison to the active sites of animal and plant enzymes, consistent with the observed preferred para-methylation and position promiscuity. Lys(3) close to the N terminus of the recombinant protein appears to play a key role in the activity of the enzyme. The possible implications of these results with respect to modifications of precursors of polymers like lignin are discussed.

  • Organizational Affiliation

    Department of Physical Biotechnology, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale) 06099, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
O-methyltransferase232Synechocystis sp. PCC 6803Mutation(s): 0 
EC: 2.1.1
Find proteins for Q55813 (Synechocystis sp. (strain PCC 6803 / Kazusa))
Explore Q55813 
Go to UniProtKB:  Q55813
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ55813
Sequence Annotations
  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.152 
  • R-Value Observed: 0.156 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.622α = 90
b = 57.622β = 90
c = 119.834γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
CrystalCleardata 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: 2008-06-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-10-25
    Changes: Refinement description
  • Version 1.3: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description