Molecular and General Genetics MGG

, Volume 149, Issue 1, pp 33–42

Assembly of the mitochondrial membrane system XVIII

Genetic loci on mitochondrial DNA involved in cytochrome b biosynthesis
  • Alexander Tzagoloff
  • Francoise Foury
  • Anna Akai


  1. 1.

    Fourteen cytoplasmic mutants of Saccharomyces cerevisiae with a specific deficiency of cytochrome b have been studied. The mutations have been shown to occur in two separate genetic loci, COB 1 and COB 2. These loci can be distinguished by mitxmit crosses. Pairwise crosses of cytochrome b mutants belonging to different loci yield 4–6% wild type recombinants corresponding to recombinational frequencies of 8–12%. In intra-locus crosses, the recombinational frequencies range from 1% to less than 0.01%. The two loci can also be distinguished by mit × ρ crosses. Twenty ρ testers have been isolated of which ten preferentially restore mutations in COB 1 and ten others in COB 2.

  2. 2.

    The COB 1 and COB 2 loci have been localized on mitochondrial DNA between the two antibiotic resistance loci OLI 1 and OLI 2 in the order OLI 2-COB 2-COB 1-OLI 1. The results of mitxmit and mit × ρ crosses have also been used to map the cytochrome b mutations relative to each other. The maps obtained by the two independent methods are in good agreement.

  3. 3.

    Mutations in COB 1 have been found to be linked to the OLI1 locus in some but not in other strains of S. cerevisiae. This evidence suggests that there may be a spacer region between the two loci whose length varies from strain to strain.

  4. 4.

    Two mutations in COB 2 have been found to cause a loss of a mitochondrial translation product corresponding to the cytochrome b apoprotein. Instead of the wild type protein the mutants have a new low-molecular weight product which is probably a fragment of cytochrome b. The fact that the mutations revert suggests that they are nonsense mutations in the structural gene of cytochrome b.



Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Deutsch, J., Dujon, B., Netter, P., Petrochilo, E., Slonimski, P.P., Bolotin-Fukuhara, M.: Mitochondrial genetics VI. The petite mutation in Saccharomyces cerevisiae: Interrelations between the loss of the 42-1 factor and the loss of the drug resistance mitochondrial genetic markers. Genetics 76, 195–219 (1974)Google Scholar
  2. Dujon, B., Slonimski, P.P., Weill, L.: Mitochondrial genetics IX. A model of recombination and segregation of mitochondrial genomes in Saccharomyces cerevisiae. Genetics 78, 415–437 (1974)Google Scholar
  3. Fukuhara, H., Bolotin-Fukuhara, M., Hsu, H.-J., Rabinowitz, M.: Deletion mapping of mitochondrial transfer RNA genes in Saccharomyces cerevisiae by means of cytoplasmic petite mutants. Molec. gen. Genet. 145, 7–17 (1976)Google Scholar
  4. Foury, F., Tzagoloff, A.: Localization in yeast mitochondrial DNA of mutations leading to a loss of rutamycin-sensitive adenosine triphosphatase. Europ. J. Biochem. 68, 113–119 (1976a)Google Scholar
  5. Foury, F., Tzagoloff, A.: Assembly of the mitochondrial membrane system XIX. Genetic characterization of mit mutants with deficiencies in cytochrome oxidase and coenzyme QH2-cytochrome c reductase. Molec. gen. Genet. 149, 43–50 (1976b)Google Scholar
  6. Katan, M.B., Groot, G.S.P.: In (E. Quagliariello, S. Papa, F. Palmieri, E.C. Slater, N. Siliprandi, eds.). Electron transfer chains and oxidative phosphorylation, pp. 127–132. Amsterdam: North Holland Press. 1975Google Scholar
  7. Needleman, R.B., Tzagoloff, A.: Breakage of Yeast: A method for processing multiple samples. Anal. Biochem. 64, 545–549 (1975)Google Scholar
  8. Schweyen, R.J., Weiss-Brummer, B., Backhaus, B., Kaudewitz, F.: In (A. Kroon, S. Saccone, eds.). The genetic function of mitochondrial DNA. Amsterdam: North Holland Press 1976 (in press)Google Scholar
  9. Slonimski, P.P., Tzagoloff, A.: Localization in yeast mitochondrial DNA of mutations expressed in a deficiency of cytochrome oxidase and/or coenzyme QH2-cytochrome c reductase. Europ. J. Biochem. 61, 27–41 (1976)Google Scholar
  10. Studier, F.W.: Analysis of bacteriophage T7 early RNAs and proteins in slab gels. J. molec. Biol. 79, 237–248 (1973)Google Scholar
  11. Trembath, M.K., Molloy, P.L., Sriprakash, K.S., Cutting, G.J., Linnane, A.W., Lukins, H.B.: Biogenesis of mitochondria 44. Comparative studies and mapping of mitochondrial oligomycin-resistance mutations in yeast based on gene recombination and petite deletion analysis. Molec. gen. Genet. 145, 43–52 (1976)Google Scholar
  12. Tzagoloff, A., Akai, A., Needleman, R.B.: Assembly of the mitochondrial membrane system: Isolation of nuclear and cytoplasmic mutants of Saccharomyces cerevisiae with specific defects in mitochondrial functions. J. Bact. 122, 826–831 (1975b)Google Scholar
  13. Tzagoloff, A., Akai, A., Needleman, R.B.: Assembly of the mitochondrial membrane system: Characterization of nuclear mutants of Saccharomyces cerevisiae with defects in mitochondrial ATPase and respiratory enzymes. J. biol. Chem. 250, 8228–8235 (1975c)Google Scholar
  14. Tzagoloff, A., Akai, A., Needleman, R.B., Zulch, G.: Assembly of the mitochondrial membrane system: Cytoplasmic mutants of Saccharomyces cerevisiae with lesions in enzymes of the respiratory chain and in the mitochondrial ATPase. J. biol. Chem. 250, 8236–8242 (1975a)Google Scholar
  15. Weiss, H., Ziganke, B.: Cytochrome b in Neurospora crassa mitochondria. Site of translation of the heme protein. Europ. J. Biochem. 41, 63–71 (1974)Google Scholar

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • Alexander Tzagoloff
    • 1
  • Francoise Foury
    • 1
  • Anna Akai
    • 1
  1. 1.The Public Health Research Institute of the City of New York, Inc.New YorkUSA

Personalised recommendations