New class of bacterial membrane oxidoreductases

Biochemistry. 2005 Aug 2;44(30):10037-45. doi: 10.1021/bi047267l.


A new class of bacterial multisubunit membrane-bound electron-transfer complexes has been identified based on biochemical and bioinformatic data. It contains subunits homologous to the three-subunit molybdopterin oxidoreductases and four additional subunits, two of which are c-type cytochromes. The complex was purified from the filamentous anoxygenic phototrophic bacterium Chloroflexus aurantiacus, and putative operons for similar complexes were identified in a wide range of bacteria. In most cases, the presence of the new complex is anticorrelated with the cytochrome bc or bf electron-transfer complex, suggesting that it replaces it functionally. This appears to be a widespread yet previously unrecognized protein complex involved in energy metabolism in bacteria.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / classification*
  • Bacterial Proteins / genetics
  • Chloroflexus / enzymology*
  • Chloroflexus / genetics
  • Computational Biology
  • Cytochromes c / chemistry
  • Cytochromes c / classification
  • Cytochromes c / genetics
  • Electron Transport / genetics
  • Electron Transport Complex IV / chemistry*
  • Electron Transport Complex IV / classification*
  • Electron Transport Complex IV / genetics
  • Genome, Bacterial
  • Membrane Proteins / chemistry*
  • Membrane Proteins / classification*
  • Membrane Proteins / genetics
  • Molecular Sequence Data
  • Multigene Family
  • Operon
  • Phylogeny
  • Protein Subunits / chemistry
  • Protein Subunits / classification
  • Protein Subunits / genetics
  • Structural Homology, Protein


  • Bacterial Proteins
  • Membrane Proteins
  • Protein Subunits
  • Cytochromes c
  • Electron Transport Complex IV