Abstract
The template activity of rat thymus chromatin for Escherichia coli DNA polymerase I has been found to amount to only 6% of that of pure DNA. Assays have been carried out on chromatin in 0.05 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 is restricted to certain 'accessible' DNA zones in chromatin. After γ irradiation of the chromatin, the template activity increases with increasing dose up to a certain level and then decreases. It is therefore proposed that both active and inactive binding sites for DNA polymerase are formed on irradiation. Assays on a chromatin polylysine complex indicate that the new initiation sites occur in the 'accessible' zones.
| Original language | English |
|---|---|
| Pages (from-to) | 259-265 |
| Number of pages | 6 |
| Journal | European Journal of Biochemistry |
| Volume | 35 |
| Issue number | 2 |
| Publication status | Published - 1973 |