title: Cytochrome c oxidase assembly factors with a thioredoxin fold are conserved among prokaryotes and eukaryotes.
abstract: Cytochrome c oxidase (COX) is a multi-subunit terminal oxidase of the eukaryotic respiratory chain involved in the reduction of oxygen to water. Numerous lines of evidence suggest that the assembly of COX is a multi-step, assisted process that depends on several assembly factors with largely unknown functions. Sco1/2 proteins have been isolated as high-copy number suppressors of a deletion of copper chaperone Cox 17, implicating Sco1/2 in copper transport to COX subunits I or II. Here I report the similarity of Sco1/2 assembly factors to peroxiredoxins and thiol:disulfide oxidoreductases with a thioredoxin fold, suggesting that Sco-related proteins perform a catalytic rather than a copper transport function. Reported sequence similarities, together with the functional role of bacterial Sco-related proteins suggest that Sco-related proteins represent a new class of membrane-anchored thiol:disulfide oxidoreductases involved in COX maturation.
authors.affiliation: Howard Hughes Medical Institute, University of Michigan Medical Center, Ann Arbor 48109-0650, USA. yurii@umich.edu
authors.forename: Y V
authors.initials: YV
authors.lastname: Chinenov
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D017124:Conserved Sequence; D000079922:Copper Transport Proteins; D003576:Electron Transport Complex IV / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D013879:Thioredoxins / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; C491006:COX17 protein, human; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D000079922:Copper Transport Proteins; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D011506:Proteins; C489345:SCO1 protein, human; C400285:SCO2 protein, human; D013879:Thioredoxins; D003576:Electron Transport Complex IV