Nuclear functions required for cytochrome c oxidase biogenesis in Saccharomyces cerevisiae. Characterization of mutants in 34 complementation groups

• Published in: The Journal of biological chemistry Vol. 261; no. 25; pp. 11872 - 11879
• Main Authors: McEwen, J E, Ko, C, Kloeckner-Gruissem, B, Poyton, R O
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 05.09.1986; American Society for Biochemistry and Molecular Biology
• Subjects: Biological and medical sciences; Cell Nucleus - physiology; Cell structures and functions; Electron Transport Complex IV - genetics; Electron Transport Complex IV - metabolism; Fundamental and applied biological sciences. Psychology; Genetic Complementation Test; GENETICA; GENETICS; GENETIQUE; GENOMAS; GENOME; GENOMES; Macromolecular Substances; MITOCHONDRIA; Mitochondria - enzymology; Mitochondria and cell respiration; MITOCHONDRIE; MITOCONDRIA; Molecular and cellular biology; MUTANT; MUTANTES; MUTANTS; Mutation; OXIDOREDUCTASES; OXIDORREDUCTASAS; OXYDOREDUCTASE; SACCHAROMYCES CEREVISIAE; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae - genetics; Species Specificity; Spectrophotometry; Cytochrome c oxidase; Yeast; Enzyme; Cell nucleus; Biosynthesis; Mitochondrial DNA; Gene expression; Fungi; Mitochondria; Molecular assembly; DNA; Ascomycetes; Complementation; Mutation; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)67323-5

To identify nuclear functions required for cytochrome c oxidase biogenesis in yeast, recessive nuclear mutants that are deficient in cytochrome c oxidase were characterized. In complementation studies, 55 independently isolated mutants were placed into 34 complementation groups. Analysis of the content of cytochrome c oxidase subunits in each mutant permitted the definition of three phenotypic classes. One class contains three complementation groups whose strains carry mutations in the COX4, COX5a, or COX9 genes. These genes encode subunits IV, Va, and VIIa of cytochrome c oxidase, respectively. Mutations in each of these structural genes appear to affect the levels of the other eight subunits, albeit in different ways. A second class contains nuclear mutants that are defective in synthesis of a specific mitochondrial-encoded cytochrome c oxidase subunit (I, II, or III) or in both cytochrome c oxidase subunit I and apocytochrome b. These mutants fall into 17 complementation groups. The third class is represented by mutants in 14 complementation groups. These strains contain near normal amounts of all cytochrome c oxidase subunits examined and therefore are likely to be defective at some step in holoenzyme assembly. The large number of complementation groups represented by the second and third phenotypic classes suggest that both the expression of the structural genes encoding the nine polypeptide subunits of cytochrome c oxidase and the assembly of these subunits into a functional holoenzyme require the products of many nuclear genes.