[Synthesis of RNA and proteins with exogenous template in the DNA-directed cell-free system from Escherichia coli B. after UV-irradiation].
The RNA and protein synthesis was studied in the DNA-directed cell-free system with extracts and ribosomes of intact and ultraviolet (UV) irradiated E. coli B. The UV-doses used did not kill the cells, but produced noticeable morphological changes. DNA of bacteriophage T2 was used as a template for the RNA synthesis. All the UV-doses used cause an approximately equal decrease in the incorporation of uracil-14C into the acid-insoluble sediment in assays incubated with the extracts of the irradiated cells. The presence of ribosomes from the irradiated cells does not affect the uracil-14C incorporation. With the lower UV-doses incorporation of 14C-labelled amino acids into the acid-insoluble seciment by the irradiated cells extract decreases to the same degree as the uracil-14C incorporation. This may be the result of proportional decrease in the intensity of total RNA and m-RNA synthesis. The intensity of 14C-labelled amino-acid 14C incorporation with the ribosomes from the cells irradiated with lower UV-doses is decreased too. This testifies to a direct effect of uv on the ribosomes. With an increase in the UV-doses these effects disappear. It is supposed that the applied doses of UV-irradiation change differently the properties of the components of RNA- and protein-synthesing systens. This discrepancy becomes more noticeable with an increase in UV-dose.
D001426:Bacterial Proteins / Q000096:biosynthesis*; D003090:Coliphages; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism / Q000528:radiation effects*; D012329:RNA, Bacterial / Q000096:biosynthesis*; D011830:Radiation Effects; D012270:Ribosomes / Q000378:metabolism / Q000528:radiation effects; D013698:Templates, Genetic; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004279:DNA, Viral; D012329:RNA, Bacterial