From respiratory supercomplexes to megacomplexes

Cellular energy is produced in mitochondria by respiratory enzymes in a process called oxidative phosphorylation. Respiratory enzymes are large proteins embedded in the inner mitochondrial membrane which can occur either as individual enzymes or organize into larger assemblies called super- and megacomplexes. Originally, supercomplex organization was not generally accepted, but nowadays, their existence is clear. However, the functional aspects are still in the dark. In this overview, we will briefly touch upon the history of supercomplex research, the variation of the supercomplex compositions and shed light on the challenges of studying their functional aspects.