Cytochrome bc complexes: a common core of structure and function surrounded by diversity in the outlying provinces

Curr Opin Struct Biol. 2004 Aug;14(4):432-9. doi: 10.1016/


The atomic-level picture of transmembrane protein complexes in the photosynthetic membrane has now been completed by the recent publication of crystal structures of cytochrome b(6)f and photosystem II. The two structures of cytochrome b(6)f, together with previously reported structures of the cytochrome bc(1) respiratory complex, provide a basis for understanding the central electron and proton transfer events of photosynthesis and respiration. The protein structures and charge transfer events within the core of the complexes are highly similar, but the complexes differ in subunit and chromophore composition in proportion to the distance from the central redox site within the membrane near the electropositive side.

Publication types

  • Review

MeSH terms

  • Biological Transport
  • Cytochrome b6f Complex / chemistry*
  • Cytochrome b6f Complex / metabolism
  • Electron Transport
  • Electron Transport Complex III / chemistry*
  • Electron Transport Complex III / metabolism
  • Models, Molecular*
  • Photosynthesis / physiology*
  • Protein Conformation
  • Protons*
  • Structure-Activity Relationship
  • Thylakoids / metabolism*


  • Protons
  • Cytochrome b6f Complex
  • Electron Transport Complex III