Function and structure of complex II of the respiratory chain

Annu Rev Biochem. 2003;72:77-109. doi: 10.1146/annurev.biochem.72.121801.161700.


Complex II is the only membrane-bound component of the Krebs cycle and in addition functions as a member of the electron transport chain in mitochondria and in many bacteria. A recent X-ray structural solution of members of the complex II family of proteins has provided important insights into their function. One feature of the complex II structures is a linear electron transport chain that extends from the flavin and iron-sulfur redox cofactors in the membrane extrinsic domain to the quinone and b heme cofactors in the membrane domain. Exciting recent developments in relation to disease in humans and the formation of reactive oxygen species by complex II point to its overall importance in cellular physiology.

Publication types

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

MeSH terms

  • Animals
  • Catalysis
  • Electron Transport
  • Electron Transport Complex II / chemistry*
  • Electron Transport Complex II / genetics
  • Electron Transport Complex II / metabolism*
  • Flavin-Adenine Dinucleotide / chemistry
  • Heme / metabolism
  • Humans
  • Iron-Sulfur Proteins / chemistry
  • Iron-Sulfur Proteins / metabolism
  • Models, Molecular
  • Protein Structure, Tertiary
  • Protein Subunits
  • Reactive Oxygen Species / chemistry
  • Reactive Oxygen Species / metabolism


  • Iron-Sulfur Proteins
  • Protein Subunits
  • Reactive Oxygen Species
  • Flavin-Adenine Dinucleotide
  • Heme
  • Electron Transport Complex II