Certain cysteine-containing proteins of the mitochondrial intermembrane space are imported from the cytosol with the help of the Mia40 protein via a disulfide relay system. What drives the unidirectional import of these proteins? Are these proteins reduced or oxidized at their cysteine residues upon import?
A) ATP hydrolysis; oxidized B) The electron-transport chain; oxidized C) ATP hydrolysis; neither oxidized nor reduced D) ATP hydrolysis; reduced E) The electron-transport chain; reduced