<unk> -coenzyme Q reductase (EC 1.3.5.1 ;<unk>  is an enzyme complex bound to the  inner mitochondrial membrane.  It is the only enzyme that participates in both  the citric acid cycle and the mitochondrial electron transport chain (in this role it is often called Complex II). It is the only citric acid cycle enzyme that is membrane-bound.  It is  found in many aerobic and anaerobic organisms including Escherichia coli.  The enzyme complex is a heterotetramer divided into three domains:<unk> HA, the catalytic domain;<unk> HB, the electron transfer subunit;<unk> HC/SDHD, the dimeric membrane anchor that contains β -type heme.
Succinate dehydrogenase
Aldehyde dehydrogenase
Oxoglutarate dehydrogenase
D-amino acid dehydrogenase
NADH dehydrogenase
Formate dehydrogenase
Glucose-6-phosphate dehydrogenase
Phosphoglucomutase