Sign Up for a Free Account

Schematic diagram of complex II

Schematic diagram of the heteromeric structure of complex II, showing its 4 subunits and their interaction with substrates and cofactors. Complex II couples the oxidation of succinate to fumarate with the reduction of ubiquinone (coenzyme Q) to ubiquinol. (Courtesy of Wikimedia Commons. Public domain.)

Associated Disorders

  • Cardiomyopathy
  • Kearns-Sayre syndrome
  • Late-onset progressive neurodegeneration
  • Leigh disease
  • Seizures