The nuclear-coded subunits of yeast cytochrome c oxidase. II. The amino acid sequence of subunit VIII and a model for its disposition in the inner mitochondrial membrane

• Published in: The Journal of biological chemistry Vol. 259; no. 10; pp. 6571 - 6574
• Main Authors: Power, S D, Lochrie, M A, Patterson, T E, Poyton, R O
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 25.05.1984; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Cell Nucleus - metabolism; Electron Transport Complex IV - genetics; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Horses; Intracellular Membranes - enzymology; Macromolecular Substances; Mitochondria - enzymology; Mitochondria, Heart - enzymology; Oxidoreductases; Protein Conformation; Protein Processing, Post-Translational; Saccharomyces cerevisiae - enzymology; Species Specificity; Molecular arrangement; Cytochrome c oxidase; Mitochondria; Yeast; Purification; Molecular structure; Enzyme; Subunit; Internal membrane
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(20)82179-6

The amino acid sequence of subunit VIII from yeast cytochrome c oxidase is reported. This 47-residue (Mr = 5364) amphiphilic polypeptide has a polar NH2 terminus, a hydrophobic central section, and a dilysine COOH terminus. An analysis of local hydrophobicity and predicted secondary structure along the peptide chain predicts that the hydrophobic central region is likely to be transmembranous. Subunit VIII from yeast cytochrome c oxidase exhibits 40.4% homology to bovine heart cytochrome c oxidase subunit VIIc , at the level of primary structure. Secondary structures and hydrophobic domains predicted from the sequences of both polypeptides are also highly conserved. From the location of hydrophobic domains and the positions of charged amino acid residues we have formulated a topological model for subunit VIII in the inner mitochondrial membrane.