Abstract
Mitochondrial and cytoplasmic ribosomes from Tetrahymena pyriformis have been isolated and studied by the techniques of polyacrylamide gel electrophoresis and electron microscopy used in conjunction. Although the two ribosome types show the same coefficient of sedimentation (80S) in sucrose gradients, they can be distinguished by gel electrophoresis: mitoribosomes migrate in a single band, considerably slower than the cytoribosome band. Electron microscope observations of negatively stained cytoribosomes show typical rounded or triangular profiles, about 275 x 230 Å; mitoribosome profiles are much larger and clearly elongate, about 370 x 240 Å. An electron-opaque spot delimits two nearly equal size subunits. In mixtures of mito- and cytoribosomes, each type can be recognized by its characteristic electrophoretic mobility and by its distinctive fine structure. Cytoribosomal 60S and 40S subunits each produce a distinct electrophoretic band. On the contrary, neither electrophoretic analysis, using a variety of conditions, nor electron microscopy is able to discern two different subunit types in the single 55S mitoribosomal subunit peak. Electrophoretic analysis of RNA shows that both ribosomal RNA species are present in the mitoribosomal subunit fraction. These results establish that mitoribosomes from T. pyriformis dissociate into two subunits endowed with the same sedimentation coefficient, the same electrophoretic mobility, and a similar morphology.
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- Allen N. E., Suyama Y. Protein synthesis in vitro with Tetrahymena mitochondrial ribosomes. Biochim Biophys Acta. 1972 Feb 15;259(3):369–377. doi: 10.1016/0005-2787(72)90311-5. [DOI] [PubMed] [Google Scholar]
- Borst P. Mitochondrial nucleic acids. Annu Rev Biochem. 1972;41:333–376. doi: 10.1146/annurev.bi.41.070172.002001. [DOI] [PubMed] [Google Scholar]
- Bruskov V. I., Kiselev N. A. Electron microscope study of the structure of Escherichia coli riboomes and CM-like particles. J Mol Biol. 1968 Nov 14;37(3):367–377. doi: 10.1016/0022-2836(68)90108-3. [DOI] [PubMed] [Google Scholar]
- Dahlberg A. E., Dingman C. W., Peacock A. C. Electrophoretic characterization of bacterial polyribosomes in agarose-acrylamide composite gels. J Mol Biol. 1969 Apr 14;41(1):139–147. doi: 10.1016/0022-2836(69)90131-4. [DOI] [PubMed] [Google Scholar]
- Hjertén S., Jerstedt S., Tiselius A. Electrophoretic "particle sieving" in polyacrylamide gels as applied to ribosomes. Anal Biochem. 1965 May;11(2):211–218. doi: 10.1016/0003-2697(65)90007-2. [DOI] [PubMed] [Google Scholar]
- Loening U. E. The fractionation of high-molecular-weight ribonucleic acid by polyacrylamide-gel electrophoresis. Biochem J. 1967 Jan;102(1):251–257. doi: 10.1042/bj1020251. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lutsch G., Bielka H., Wahn K., Stahl J. Studies on the structure of aminal ribosomes. 3. Electron microscopic investigations of isolated rat liver ribosomes and their subunits. Acta Biol Med Ger. 1972;29(6):851–876. [PubMed] [Google Scholar]
- Mikhailova I. Iu, Bogdanov A. A. Elektroforez ribosom i ribosomnykh RNK v poliakrilamidnom gele. Biokhimiia. 1970 May-Jun;35(3):403–408. [PubMed] [Google Scholar]
- Nonomura Y., Blobel G., Sabatini D. Structure of liver ribosomes studied by negative staining. J Mol Biol. 1971 Sep 14;60(2):303–323. doi: 10.1016/0022-2836(71)90296-8. [DOI] [PubMed] [Google Scholar]
- Schutgens R. B., Reijnders L., Hoekstra S. P., Borst P. Transcription of Tetrahymena mitochondrial DNA in vivo. Biochim Biophys Acta. 1973 May 18;308(3):372–380. doi: 10.1016/0005-2787(73)90330-4. [DOI] [PubMed] [Google Scholar]
- Tiollais P., Galibert F., Lepetit A., Auger M. A. L'électrophorèse des acides ribonucléiques en gel de polyacrylamide. Biochimie. 1972;54(3):339–354. doi: 10.1016/s0300-9084(72)80213-x. [DOI] [PubMed] [Google Scholar]
- Vignais P. V., Stevens B. J., Huet J., André J. Mitoribosomes from Candida utilis. Morphological, physical, and chemical characterization of the monomer form and of its subunits. J Cell Biol. 1972 Sep;54(3):468–492. doi: 10.1083/jcb.54.3.468. [DOI] [PMC free article] [PubMed] [Google Scholar]