Segall A M, Nash H A
Laboratory of Molecular Biology, NIMH, Bethesda, MD 20892-0036.
EMBO J. 1993 Dec;12(12):4567-76. doi: 10.1002/j.1460-2075.1993.tb06145.x.
Bacteriophage lambda uses site-specific recombination to move its DNA into and out of the Escherichia coli genome. The recombination event is mediated by the recombinase integrase (Int) together with several accessory proteins through short specific DNA sequences known as attachment sites. A gel mobility shift assay has been used to show that, in the absence of accessory proteins, Int can align and hold together two DNA molecules, each with an attachment site, to form stable non-covalent 'bimolecular complexes'. Each attachment site must have both core and arm binding sites for Int to participate in a bimolecular complex. These stable structures can be formed between pairs of attL and attP attachment sites, but cannot include attB or attR sites; they are inhibited by integration host factor (IHF) protein. The bimolecular complexes are shown to represent a synaptic intermediate in the reaction in which Int protein promotes the IHF-independent recombination of two attL sites. These complexes should enable a detailed analysis of synapsis for this pathway.
噬菌体λ利用位点特异性重组将其DNA移入和移出大肠杆菌基因组。重组事件由重组酶整合酶（Int）与几种辅助蛋白通过称为附着位点的短特定DNA序列介导。凝胶迁移率变动分析已用于表明，在没有辅助蛋白的情况下，Int可以使两个各带有一个附着位点的DNA分子对齐并结合在一起，形成稳定的非共价“双分子复合物”。每个附着位点必须同时具有Int参与双分子复合物的核心和臂结合位点。这些稳定结构可在attL和attP附着位点对之间形成，但不包括attB或attR位点；它们受到整合宿主因子（IHF）蛋白的抑制。双分子复合物被证明代表了Int蛋白促进两个attL位点的不依赖IHF的重组反应中的突触中间体。这些复合物应能对该途径的突触进行详细分析。
