Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of cytochrome oxidase in Saccharomyces cerevisiae was recently shown to require a protein encoded by the nuclear gene COX10. This protein was found to be homologous to the putative protein product of the open reading frame ORF1 reported in one of the cytochrome oxidase operons of Paracoccus denitrificans. In the present study we demonstrate the existence in yeast of a second nuclear gene, COX11, whose encoded protein is homologous to another open reading frame (ORF3) present in the same operon of P. denitrificans. Mutations in COX11 elicit a deficiency in cytochrome oxidase. In this and in other respects cox11 and cox10 mutants have very similar phenotypes. An antibody has been obtained against the yeast COX11 protein. The antibody recognizes a 28 kd protein in yeast mitochondria, consistent with the size of the protein predicted from the sequence of COX11. The COX11 protein is tightly associated with the mitochondrial membrane but is not a component of purified cytochrome oxidase. An analysis of cytochrome oxidase subunits in wild type and in a cox11 mutant suggests that the COX11 protein is not required either for synthesis or transport of the subunit polypeptides into mitochondria. It seems more probable that COX11 protein exerts its effect at some terminal stage of enzyme synthesis, perhaps in directing assembly of the subunits.
 ...
PMID:Cytochrome oxidase assembly in yeast requires the product of COX11, a homolog of the P. denitrificans protein encoded by ORF3. 216 32

COX10 and COX11 are nuclear genes of Saccharomyces cerevisiae whose products are localized in mitochondria and are required for the synthesis of cytochrome oxidase. Genes homologous to COX10 are present in at least four different bacterial cytochrome oxidase operons. The bacterial gene, termed cyoE, has recently been proposed to code for a farnesyl transferase that converts protoheme to heme O (Saiki et al. (1992), Biochem. Biophys. Res. Commun. 189, 1491-1497). In this communication we report that the COX10 protein, like the product of cyoE is needed for heme A synthesis. Analyses of the heme constituents in a cox11 mutant indicate the absence of heme A and presence of a novel heme with chromatographic properties indistinguishable from those of heme O. This evidence suggests that the COX11 protein may be another heme A biosynthetic enzyme involved in forming the formyl group at position 8 of the porphyrin ring.
 ...
PMID:On the functions of the yeast COX10 and COX11 gene products. 811 33