噬菌体φX174 A蛋白对超螺旋φX174 DNA的酶学特性：滚环DNA复制终止的模型

van der Ende A, Langeveld S A, Teertstra R, van Arkel G A, Weisbeek P J

Nucleic Acids Res. 1981 May 11;9(9):2037-53. doi: 10.1093/nar/9.9.2037.

Incubation of phi X174 replication form I DNA with the A* protein of phi X174 in the presence of MN2+ results in the formation of three different types of DNA molecules: open circular form DNA (RFII), linear form DNA (RFIII) and the relaxed covalently closed form DNA (RFIV). The RFII and RFIII DNAs are shown to be A* protein-DNA complexes by electron microscopy using the protein labeling technique of Wu and Davidson (1). The linear double-stranded RFIII DNA molecule carries at one end a covalently attached A* protein whereas at the other end of the molecule the single-stranded termini are covalently linked to each other. The structure of the RFIII DNA shows its way of formation. The described properties of the A* protein indicate the way the larger A protein functions in the termination step of the rolling-circle type of phi X174 DNA replication.

在Mn2+存在的情况下，将φX174复制形式I DNA与φX174的A蛋白一起温育，会形成三种不同类型的DNA分子：开环形式DNA（RFII）、线性形式DNA（RFIII）和松弛共价闭合形式DNA（RFIV）。通过使用Wu和Davidson（1）的蛋白质标记技术进行电子显微镜观察，显示RFII和RFIII DNA是A蛋白-DNA复合物。线性双链RFIII DNA分子一端带有共价连接的A蛋白，而在分子的另一端，单链末端彼此共价连接。RFIII DNA的结构显示了其形成方式。所描述的A蛋白的特性表明了较大的A蛋白在φX174 DNA滚环型复制终止步骤中的作用方式。