DNA Synthesis in Isolated Yeast Mitochondria
| Autor: | C. V. Lusena, L. Zeman |
|---|---|
| Rok vydání: | 1974 |
| Předmět: |
Mitochondrial DNA
Time Factors Saccharomyces cerevisiae DNA Single-Stranded Haploidy Nucleic Acid Denaturation Tritium DNA Mitochondrial chemistry.chemical_compound Centrifugation Density Gradient Thymine Nucleotides Centrifugation Denaturation (biochemistry) Carbon Radioisotopes Deoxyribonucleases biology DNA synthesis Adenine General Medicine biology.organism_classification Mitochondria Nuclear DNA Molecular Weight Isopycnic Biochemistry chemistry Isotope Labeling Nucleic Acid Renaturation Spectrophotometry Ultraviolet DNA Thymidine |
| Zdroj: | Canadian Journal of Biochemistry. 52:941-949 |
| ISSN: | 0008-4018 |
| DOI: | 10.1139/o74-132 |
| Popis: | Isolated yeast (Saccharomyces cerevisiae) mitochondria incorporate radioactive precursors into mitochondrial DNA. This in vitro labelled DNA was characterized by isopycnic and sedimentation velocity centrifugation both in the native and denatured state. The profiles of isopycnic CsCl gradients obtained by centrifugation in a fixed-angle rotor are skewed toward high density. The skew is neither due to the presence of in vitro labelled nuclear DNA nor due to random breaks in mitochondrial DNA which would reveal, then, its heterogeneity in base composition. The in vitro labelled DNA is reproducibly recovered as a class of molecules sedimenting at about 5–8 S, indicating a molecular weight of 1 × 105 – 4 × 105 daltons, while the smallest in vivo labelled fragments sediment at about 13–14 S, corresponding to 1.6 × 106 – 2.0 × 106 daltons. After denaturation, the in vitro labelled DNA molecules sediment at about 2–5 S, corresponding to a single-strand molecular weight of 1 × 104 – 7 × 104 daltons, which is about one hundred times less than the observed size of the denatured in vivo labelled molecules. |
| Databáze: | OpenAIRE |
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