Crystal structure of a bacterial non-haem iron hydroxylase that catalyses the biological oxidation of methane

Nature. 1993 Dec 9;366(6455):537-43. doi: 10.1038/366537a0.


The 2.2 A crystal structure of the 251K alpha 2 beta 2 gamma 2 dimeric hydroxylase protein of methane monooxygenase from Methylococcus capsulatus (Bath) reveals the geometry of the catalytic di-iron core. The two iron atoms are bridged by exogenous hydroxide and acetate ligands and further coordinated by four glutamate residues, two histidine residues and a water molecule. The dinuclear iron centre lies in a hydrophobic active-site cavity for binding methane. An extended canyon runs between alpha beta pairs, which have many long alpha-helices, for possible docking of the reductase and coupling proteins required for catalysis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Cytochrome P-450 Enzyme System / chemistry
  • Iron / analysis
  • Macromolecular Substances
  • Methane / metabolism*
  • Methylococcaceae / enzymology*
  • Models, Molecular
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Oxygenases / chemistry*
  • Oxygenases / metabolism
  • Protein Conformation*
  • Protein Structure, Secondary*
  • X-Ray Diffraction


  • Macromolecular Substances
  • Cytochrome P-450 Enzyme System
  • Iron
  • Oxygenases
  • methane monooxygenase
  • Methane