The Structure of Flavocytochrome C Sulfide Dehydrogenase From a Purple Phototrophic Bacterium

Science. 1994 Oct 21;266(5184):430-2. doi: 10.1126/science.7939681.


The structure of the heterodimeric flavocytochrome c sulfide dehydrogenase from Chromatium vinosum was determined at a resolution of 2.53 angstroms. It contains a glutathione reductase-like flavin-binding subunit and a diheme cytochrome subunit. The diheme cytochrome folds as two domains, each resembling mitochondrial cytochrome c, and has an unusual interpropionic acid linkage joining the two heme groups in the interior of the subunit. The active site of the flavoprotein subunit contains a catalytically important disulfide bridge located above the pyrimidine portion of the flavin ring. A tryptophan, threonine, or tyrosine side chain may provide a partial conduit for electron transfer to one of the heme groups located 10 angstroms from the flavin.

Publication types

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

MeSH terms

  • Binding Sites
  • Chromatium / enzymology*
  • Computer Graphics
  • Crystallography, X-Ray
  • Cytochrome c Group / chemistry*
  • Electron Transport
  • Flavin-Adenine Dinucleotide / metabolism
  • Hydrogen Bonding
  • Models, Molecular
  • Oxidoreductases / chemistry*
  • Protein Conformation
  • Protein Structure, Secondary


  • Cytochrome c Group
  • Flavin-Adenine Dinucleotide
  • Oxidoreductases
  • flavocytochrome c sulfide dehydrogenase