An essential iteron-binding protein required for plasmid R1162 replication induces localized melting within the origin at a specific site in AT-rich DNA.
An essential iteron-binding protein required for plasmid R1162 replication induces localized melting within the origin at a specific site in AT-rich DNA.
复制标题
质粒 R1162 复制所需的一种必需的迭代子结合蛋白可诱导富含 AT 的 DNA 中特定位点的原点内的局部熔化。
DOI：
10.1128/jb.173.17.5539-5545.1991
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发表时间：
1991
影响因子：
3.2
通讯作者：
Meyer,RJ
中科院分区：
文献类型：
--
作者：
Kim,YJ;Meyer,RJ
R1162编码的蛋白RepIB对于质粒的复制是必需的，并且特异性地结合复制起点内的iteron。该蛋白导致DNA的局部熔化（由对P1核酸酶的敏感性决定）在AT丰富的起源区域内的一个位点，距离iteron结合位点约60 bp，并通过富含GC的道与它们分开。在富含AT的DNA中已经分离出点突变。这些突变干扰了起始活性，也阻止了蛋白质诱导的对P1的敏感性。这些突变之一的第二个位点抑制子映射到repIb基因中，并恢复原始功能和对P1的敏感性。结果表明RepIB和起源DNA之间的特异性相互作用在远离其主要结合位点的位置。
The R1162-encoded protein RepIB is essential for replication of the plasmid and binds specifically to iterons within the replicative origin. The protein causes the localized melting of DNA (determined by sensitivity to P1 nuclease) at a site within the AT-rich region of the origin, about 60 bp from the iteron binding sites and separated from them by a GC-rich tract. Point mutations have been isolated in the AT-rich DNA. These mutations interfere with origin activity and also prevent the protein-induced sensitivity to P1. A second-site suppressor of one of these mutations maps in the repIb gene and restores both origin function and sensitivity to P1. The results suggest a specific interaction between RepIB and origin DNA at a position distant from its primary binding site.