Hoess R H, Landy A
Proc Natl Acad Sci U S A. 1978 Nov;75(11):5437-41. doi: 10.1073/pnas.75.11.5437.
Bacteriophage lambda integrates into the chromosome of its Escherichia coli host by means of a site-specific recombination between a locus on the phage chromosome (phage att site) and a locus on the bacterial chromosome (bacterial att site). The nucleotide sequence of four lambda att sites altered in site-specific recombination has been determined. The int-dependent deletions that generated these att sites have one end point within the phage att site and extend either to the left or to the right. As a result of the new internucleotide bond created by deletion formation, these phage have alterations in the 15-base-pair common core region. The new DNA sequences brought to the att sites by the deletions, designated delta for regions to the left and delta' for regions to the right, do not share any discernible homology with their analogous counterparts in the phage att site arms, P and P', respectively, or with the bacterial att site arms, B and B', respectively. The finding of alterations in the 15-base-pair common core region necessitates a reinterpretation of the genetic properties of these att sites in site-specific recombination. The structure of these sites in relation to their genetic properties can be viewed as being consistent with a model in which the only specificity elements in int-dependent site-specific recombination are the common core region, O, and the phage arms, P and P'.
噬菌体λ通过噬菌体染色体上的一个位点（噬菌体附着位点）与细菌染色体上的一个位点（细菌附着位点）之间的位点特异性重组整合到其大肠杆菌宿主的染色体中。已经确定了在位点特异性重组中发生改变的四个λ附着位点的核苷酸序列。产生这些附着位点的int依赖性缺失在噬菌体附着位点内有一个端点，并向左或向右延伸。由于缺失形成产生的新的核苷酸间键，这些噬菌体在15个碱基对的共同核心区域有改变。缺失带到附着位点的新DNA序列，左侧区域称为δ，右侧区域称为δ'，它们分别与噬菌体附着位点臂P和P'以及细菌附着位点臂B和B'中的类似对应物没有任何可识别的同源性。在15个碱基对的共同核心区域发现改变，需要对这些附着位点在位点特异性重组中的遗传特性进行重新解释。这些位点与其遗传特性相关的结构可以被视为与一个模型一致，在该模型中，int依赖性位点特异性重组中唯一的特异性元件是共同核心区域O以及噬菌体臂P和P'。
