Siegmann D W, Werner R
Proc Natl Acad Sci U S A. 1976 Oct;73(10):3438-42. doi: 10.1073/pnas.73.10.3438.
Because of their association with protein short nascent DNA chains in Escherichia coli can be separated from other cellular DNA by chromatography on hydroxylapatite. Protein-free DNA chains of less than 500 nucleotides in length are resistant to degradation from the 5'-end by alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum); EC 3.1.3.1] and spleen phosphodiesterase (oligonucleate 3'-nucleotidohydrolase; EC 3.1.4.18). In contrast, DNA chains containing more than 500 nucleotides are degradable. From these results we conclude that short nascent DNA chains are structurally modified at their 5'-ends. The nature of this structure and its possible functions are discussed.
由于短新生DNA链与蛋白质相关联,在大肠杆菌中可以通过羟基磷灰石柱层析将其与其他细胞DNA分离。长度小于500个核苷酸的无蛋白质DNA链对碱性磷酸酶[正磷酸单酯磷酸水解酶(最适pH为碱性);EC 3.1.3.1]和脾磷酸二酯酶(寡核苷酸3'-核苷酸水解酶;EC 3.1.4.18)从5'-末端的降解具有抗性。相反,含有超过500个核苷酸的DNA链是可降解的。从这些结果我们得出结论,短新生DNA链在其5'-末端进行了结构修饰。讨论了这种结构的性质及其可能的功能。