Mitochondrial molecular chaperones

After synthesis in the cytosol, most mitochondrial proteins must
traverse mitochondrial membranes to reach their functional
location. During this process, proteins become unfolded and then
refold to attain their native conformation after crossing the lipid
bilayers. Mitochondrial molecular chaperones play an essential
mechanistic role at various steps of this process. They facilitate
presequence translocation, unfolding of the cytosol-localized
domains of precursor proteins, movement across the mitochondrial
membranes and, finally, folding of newly imported proteins within
the matrix.