Topology of Xer recombination on catenanes produced by lambda integrase.
Topology of Xer recombination on catenanes produced by lambda integrase.
复制标题
由 lambda 整合酶产生的索烷上的 Xer 重组拓扑。
DOI：
10.1006/jmbi.1999.2804
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发表时间：
1999
影响因子：
5.6
通讯作者：
S. Colloms
中科院分区：
文献类型：
--
作者：
J. Bath;D. Sherratt;S. Colloms
来自质粒pSC101的psi位点处的Xer位点特异性重组显示拓扑选择性，使得重组通常仅发生在相同环状DNA分子上的直接重复位点之间。这种分子内选择性对于psi的生物学作用是重要的，并且由辅助蛋白PepA和ArcA施加，其作用于邻近核心重组位点的辅助DNA序列。在这里，我们表明，在psi的分子内重组的选择性可以绕过多重互连索烃。Xer位点特异性重组发生相对有效的反平行psi网站位于单独的环上的右手环面catenanes含有6个或更多的节点。这种重组在索烃中引入了一个额外的节点。反平行网站上的四个节点的右手catenanes，在psi的Xer重组的正常产品，没有重组有效。此外，平行psi网站上的右手环面catenanes没有基板Xer重组。这些发现支持了一个模型，其中psi网站plectonemically相互缠绕，捕获一个精确的数量的超螺旋，转换为四个连锁节点的Xer链交换。
Xer site-specific recombination at the psi site from plasmid pSC101 displays topological selectivity, such that recombination normally occurs only between directly repeated sites on the same circular DNA molecule. This intramolecular selectivity is important for the biological role of psi, and is imposed by accessory proteins PepA and ArcA acting at accessory DNA sequences adjacent to the core recombination site. Here we show that the selectivity for intramolecular recombination at psi can be bypassed in multiply interlinked catenanes. Xer site-specific recombination occurred relatively efficiently between antiparallel psi sites located on separate rings of right-handed torus catenanes containing six or more nodes. This recombination introduced one additional node into the catenanes. Antiparallel sites on four-noded right-handed catenanes, the normal product of Xer recombination at psi, were not recombined efficiently. Furthermore, parallel psi sites on right-handed torus catenanes were not substrates for Xer recombination. These findings support a model in which psi sites are plectonemically interwrapped, trapping a precise number of supercoils that are converted to four catenation nodes by Xer strand exchange.
细菌中位点特异性 DNA 倒转的机制。
影响因子：
4
作者：
Johnson,RC
通讯作者：
Johnson,RC