Study of the template properties of chromatin for DNA polymerase I and of the effects of ionising radiation
The template activity of rat thymus chromatin for Escherichia coli DNA polymerse 1 was found to amount to only 6% of that of pure DNA. Assays were carried out on chromatin in 0.03 M NaCl, on a chromatin-polylysine complex, on the soluble and insoluble fractions of chromatin in the assay system and on DNA prepared from chromatin. The results suggest that the low activity is due only to a small extent to the insolubility of the chromatin in the assay system. Instead, it is proposed that initiation in restricted to certain accessible DNA zones in chromatin. After gamma irradiation of the chromatin, the template activity increases with increasing dose up to a certain level and then decreases. lt is therefore proposed that both active and inactive binding sites for DNA polymerase are formed on irradiation. Assays on a chromatinpolylysine complex indicate that the new initation sites occur in the accessible zones. (GE)
- Research Organization:
- Christie Hospital and Holt Radium Inst., Manchester, Eng.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-29-010354
- OSTI ID:
- 4410345
- Journal Information:
- Eur. J. Biochem., v. 35, no. 2, pp. 259-265, Other Information: Orig. Receipt Date: 30-JUN-74
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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