title: The Oxa2 protein of Neurospora crassa plays a critical role in the biogenesis of cytochrome oxidase and defines a ubiquitous subbranch of the Oxa1/YidC/Alb3 protein family.
abstract: Proteins of the Oxa1/YidC/Alb3 family mediate the insertion of proteins into membranes of mitochondria, bacteria, and chloroplasts. Here we report the identification of a second gene of the Oxa1/YidC/Alb3 family in the genome of Neurospora crassa, which we have named oxa2. Its gene product, Oxa2, is located in the inner membrane of mitochondria. Deletion of the oxa2 gene caused a specific defect in the biogenesis of cytochrome oxidase and resulted in induction of the alternative oxidase (AOD), which bypasses the need for complex IV of the respiratory chain. The Oxa2 protein of N. crassa complements Cox18-deficient yeast mutants suggesting a common function for both proteins. The oxa2 sequence allowed the identification of a new subfamily of Oxa1/YidC/Alb3 proteins whose members appear to be ubiquitously present in mitochondria of fungi, plants, and animals including humans.
authors.affiliation: Institut für Physiologische Chemie, Universität München, 81377 München, Germany.
authors.forename: Soledad
authors.initials: S
authors.lastname: Funes
authors.forename: Frank E
authors.initials: FE
authors.lastname: Nargang
authors.forename: Walter
authors.initials: W
authors.lastname: Neupert
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Herrmann
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002455:Cell Division; D004247:DNA / Q000737:chemistry; D003576:Electron Transport Complex IV / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D017353:Gene Deletion; D005816:Genetic Complementation Test; D016681:Genome, Fungal; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000502:physiology*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D009492:Neurospora crassa / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013347:Subcellular Fractions; D013997:Time Factors; D000099188:Alternative Oxidase
chemical_list: D004247:DNA; D003576:Electron Transport Complex IV; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins; D000099188:Alternative Oxidase; C409465:COX18 protein, S cerevisiae