BACTERIOPHAGE-P1 SITE-SPECIFIC RECOMBINATION .2. RECOMBINATION BETWEEN LOXP AND THE BACTERIAL CHROMOSOME
BACTERIOPHAGE-P1 SITE-SPECIFIC RECOMBINATION .2. RECOMBINATION BETWEEN LOXP AND THE BACTERIAL CHROMOSOME
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DOI：
10.1016/0022-2836(81)90376-4
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发表时间：
1981-01-01
影响因子：
5.6
通讯作者：
HOESS, R
中科院分区：
文献类型：
--
作者：
STERNBERG, N;HAMILTON, D;HOESS, R
描述了与loxP（噬菌体P1 EcoRI片段7中的一个位点）和loxB（细菌[大肠杆菌]染色体中的一个位点）之间的重组相关的事件。当片段7在噬菌体中时，向量，loxP ×loxB重组是整合了P1：7（loxP）DNA作为细菌染色体中的前噬菌体，并在前噬菌体侧翼产生2个新的杂交位点loxR和loxL。分离含有loxL、loxR和loxB位点的λ基因，并用于测量配对噬菌体杂交中所有4个lox位点之间的重组频率。loxP和loxL位点是比loxR和loxB位点更好的重组底物。重组反应中的两个配偶体都必须含有loxP或loxL位点以使重组有效。这些结果可以解释所有这些发现，这些发现涉及到P1：7 DNA和细菌染色体。特别地，该DNA整合到loxB中是低的，因为loxP ×loxB重组是低效的，并且由于loxL ×loxR重组是低效的。与此相反，集成的。P1：7 DNA插入到已经含有I-P1：7前噬菌体的染色体中的loxB相对较高，并且总是伴随着原始前噬菌体DNA的切除和随后的损失。该过程被称为通过原噬菌体置换的整合，并且可以通过假设涉及2个lox重组事件来解释（loxP. x. loxR和loxL），两者都比loxP × loxL更有效。loxB重组。对各种λ lox DNA的物理结构的分析表明，含loxP的DNA可以以两种可能的方向整合到loxB中，并且loxP × loxB可以以两种可能的方向整合到loxB中。loxB交换点位于EcoRI片段7的亚片段P1 BamHI片段9的100个碱基对区域内。将loxB位点定位于E. coli染色体的DNA序列在tolC（66 min）和dnaG（67 min）之间。
The events associated with recombination between loxP, a site in phage P1 EcoRI fragment 7, and loxB, a site in the bacterial [Escherichia coli] chromosome, are described. When fragment 7 is in a phage .lambda. vector, the product of loxP .times. loxB recombination is the integration of the .lambda.-P1:7(loxP) DNA as prophage in the bacterial chromosome and the production of 2 new hybrid sites, loxR and loxL, flanking the prophage. Lambda phages containing loxL, loxR and loxB sites were isolated and used to measure recombination frequencies between all 4 lox sites in paired phage crosses. loxP and loxL sites were much better substrates for recombination than are loxR and loxB sites. Both partners in a recombination reaction must contain either loxP or loxL sites for recombination to be efficient. These results can explain all of these findings relating to the recombination between .lambda.-P1:7 DNA and the bacterial chromosome. In particular, integration of that DNA into loxB is low because loxP .times. loxB recombination is inefficient, and excision of the resulting prophage DNA is low because loxL .times. loxR recombination is inefficient. In contrast, integration of .lambda.-P1:7 DNA into a chromosome already containing a i-P1:7 prophage at loxB is relatively high and is always accompanied by the excision and subsequent loss of the original prophage DNA. This process was called integration by prophage displacement, and it can be accounted for by postulating that 2 lox recombination events are involved (loxP .times. loxR and loxL), both of which are more efficient than is loxP .times. loxB recombination. Analysis of the physical structure of the various .lambda.lox phages indicates that loxP-containing DNA can integrate into loxB in both possible orientations, and that the loxP .times. loxB crossover point is located within a 100 base-pair region of P1 BamHI fragment 9, a subfragment of EcoRI fragment 7. The loxB site was mapped to a region of the E. coli chromosome between tolC (66 min) and dnaG (67 min).