A mitochondrial matrix copper ligand (CuL) complex, conserved in mammalian cells, is the
likely source of copper for assembly of cytochrome c oxidase (CcO) and superoxide
dismutase 1 (Sod1) within the intermembrane space (IMS) in yeast. Targeting the copper-
binding proteins human Sod1 and Crs5 to the mitochondrial matrix results in growth
impairment on non-fermentable medium caused by decreased levels of CcO. This effect is
reversed by copper supplementation. Matrix-targeted Crs5 diminished Sod1 protein within …