title: Yeast Sco1, a protein essential for cytochrome c oxidase function is a Cu(I)-binding protein.
abstract: Sco1 is a conserved essential protein, which has been implicated in the delivery of copper to cytochrome c oxidase, the last enzyme of the electron transport chain. In this study, we show for the first time that the purified C-terminal domain of yeast Sco1 binds one Cu(I)/monomer. X-ray absorption spectroscopy suggests that the Cu(I) is ligated via three ligands, and we show that two cysteines, present in a conserved motif CXXXC, and a conserved histidine are involved in Cu(I) ligation. The mutation of any one of the conserved residues in Sco1 expressed in yeast abrogates the function of Sco1 resulting in a non-functional cytochrome c oxidase complex. Thus, the function of Sco1 correlates with Cu(I) binding. Data obtained from size-exclusion chromatography experiments with mitochondrial lysates suggest that full-length Sco1 may be oligomeric in vivo.
authors.affiliation: Department of Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
authors.forename: T
authors.initials: T
authors.lastname: Nittis
authors.forename: G N
authors.initials: GN
authors.lastname: George
authors.forename: D R
authors.initials: DR
authors.lastname: Winge
mesh_terms: D020816:Amino Acid Motifs; D002352:Carrier Proteins / Q000737:chemistry*; D003300:Copper / Q000378:metabolism*; D019281:Dimerization; D003576:Electron Transport Complex IV / Q000502:physiology*; D008024:Ligands; D008565:Membrane Proteins / Q000737:chemistry* / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D008024:Ligands; D008565:Membrane Proteins; D003300:Copper; D003576:Electron Transport Complex IV