Schnos M, Zahn K, Inman R B, Blattner F R
Institute for Molecular Virology, University of Wisconsin-Madison 53706.
Cell. 1988 Feb 12;52(3):385-95. doi: 10.1016/s0092-8674(88)80031-x.
The interaction of the lambda phage initiator protein, O, with the lambda origin sequence, ori, has been investigated. Binding of O, or its amino-terminal fragment, causes a major structural change within a 60 bp AT-rich region just to the right of the O-binding site. ATP or other molecular energy sources are not required. The modification, as assayed by nuclease sensitivity, is reduced when certain ori mutant sequences, which bind O but fail to replicate, are substituted for the wild-type sequence. The modification of DNA structure caused by the interaction of O is absolutely dependent on the presence of superhelical tension at the lambda origin sequence, and has several properties consistent with a strand separation reaction. We propose that this modification is a fundamental prepriming event that is the first stage in initiation of bidirectional replication in lambda after O binding.
已对λ噬菌体起始蛋白O与λ噬菌体起源序列ori的相互作用进行了研究。O或其氨基末端片段的结合会在O结合位点右侧一个60 bp富含AT的区域内引起主要的结构变化。不需要ATP或其他分子能量来源。当某些与O结合但无法复制的ori突变序列替代野生型序列时，通过核酸酶敏感性测定的修饰会降低。由O的相互作用引起的DNA结构修饰绝对依赖于λ噬菌体起源序列处超螺旋张力的存在，并且具有与链分离反应一致的几个特性。我们提出这种修饰是一个基本的引发前事件，是O结合后λ噬菌体双向复制起始的第一阶段。
