Enzymatic RNA synthesis on irradiated DNA

Photoreactivation of template activity of UV—irradiated DNA in an RNA—polymerase system. A rapid assay for photoreactivating enzyme

“…Hagen et al [4] described a decrease in the chain length of RNA synthesized on W-DNA, so the influence of photoreactivation on chain length was studied by sucrose gradient centrifugation. The sedimentation patterns given in fig.2 show a distinct shift of the maximum to a longer chain length after It is clear that photoreactivation with respect to chain length was also incomplete.…”

Oxygen-effect as an inhibition of repair: Radiation studies on excision repair deficient mei-9L1-embryos of drosophila

“…The DNA damage can, sooner or later, cause cell death (Fig. 3) or damage of differentiation, e.g., by defects in the RNA-synthesis [14].…”

“…We assume that there are at least two kinds of damage (D1 and D2) with D1 representing the "less significant" radiation damage which leads to late death, while D2 represents the more serious type of damage. D1 could be a slight DNA-damage leading to disorders in cell proliferation and (or) in RNA-production according to Hagen et al [14]. The slight damage can be repaired; without a repair it would be fixed or could develop into heavy DNA-damage leading to cell death (early death).…”

The Induction of β-galactosidase and Tryptophanase in X-irradiatedE. ColiB and B/r

“…It is true that most of the available information about radiation-induced DNA damage and its repair in bacteria is confined to single-strand breaks (ssb), whose role in the radiation effects on transcription and translation is not yet established . However, some experimental evidence (Hagen, Ullrich, Petersen, Werner and Kroger 1970) has been produced suggesting that RNA-polymerase might bind at wrong initiator points in broken DNA and this, as suggested by Pollard and Lydersen (1972), would possibly halt the process of transcription . In any case, owing to the random distribution of radiation damage, it is difficult to understand why the transcription of inducible enzymes should be impaired when that of constitutive proteins is not affected .…”