Scher B M, Dean D H, Garro A J
J Virol. 1977 Aug;23(2):377-83. doi: 10.1128/JVI.23.2.377-383.1977.
The structure of DNA from the temperate Bacillus subtilis phage phi105 was examined by using the restriction endonuclease EcoRI and by sedimentation analysis. The DNA contains six EcoRI cleavage sites. Although eight DNA fragments were identified in the EcoRI digests, the largest of these was shown to consist of the two fragments that carry the cohesive ends of the phage DNA. In neutral gradients, the majority of whole phi105 DNA sedimented as nicked circles and the remainder as oligomers. No unit-length linear structures were detected. The associated cohesive ends could be sealed by DNA ligase from Escherichia coli and could be cleaved by S1 nuclease. On the basis of these results and previously reported studies, it appears that, as isolated from phage particles, phi105 DNA is a circular molecule that is formed from the linear structure by the association of complementary single-stranded DNA.
利用限制性内切酶EcoRI并通过沉降分析，对温和型枯草芽孢杆菌噬菌体phi105的DNA结构进行了研究。该DNA含有六个EcoRI切割位点。虽然在EcoRI酶切产物中鉴定出了八个DNA片段，但其中最大的片段被证明由携带噬菌体DNA粘性末端的两个片段组成。在中性梯度中，大多数完整的phi105 DNA以带切口的环状形式沉降，其余的以寡聚体形式沉降。未检测到单位长度的线性结构。相关的粘性末端可以被来自大肠杆菌的DNA连接酶封闭，并可以被S1核酸酶切割。基于这些结果和先前报道的研究，从噬菌体颗粒中分离出来的phi105 DNA似乎是一个环状分子，它是由线性结构通过互补单链DNA的缔合形成的。
