The yeast mitochondrion is shown to contain a pool of copper that is distinct from that
associated with the two known mitochondrial cuproenzymes, superoxide dismutase (Sod1)
and cytochrome c oxidase (CcO) and the copper-binding CcO assembly proteins Cox11,
Cox17, and Sco1. Only a small fraction of mitochondrial copper is associated with these
cuproproteins. The bulk of the remainder is localized within the matrix as a soluble, anionic,
low molecular weight complex. The identity of the matrix copper ligand is unknown, but the …