REPLICATION OF COLE2 AND COLE3 PLASMIDS - THE REGIONS SUFFICIENT FOR AUTONOMOUS REPLICATION
REPLICATION OF COLE2 AND COLE3 PLASMIDS - THE REGIONS SUFFICIENT FOR AUTONOMOUS REPLICATION
复制标题
DOI：
10.1007/bf00334689
复制
发表时间：
1988-05-01
期刊：
影响因子：
--
通讯作者：
ITOH, T
中科院分区：
文献类型：
--
作者：
HORII, T;ITOH, T
我们在colicin E2 （ColE2）和colicin E3 （ColE3）质粒的基因组上定位了足以自主复制的区域，并分析了这些区域携带的复制功能。每个质粒的1.3 kb片段足以进行自主复制。携带该片段的质粒保留了原质粒的复制特性。1.3 kb段由三个功能部分组成。首先，一个0.9公斤的区域，指定了每个质粒复制所需的至少一个反式作用因子。其次，一个0.4 kb的区域位于邻近0.9 kb区域的一端，这是表达反式作用因子所必需的，可能包含启动子。ColE2的这两个部分的交界区域参与质粒拷贝数的控制。第三部分是一个50 bp的区域，与0.9 kb区域的另一端相邻，其中包含一个顺式作用位点（起源），在这里，在反式作用因子的存在下开始复制。反式作用因子对起源的作用是质粒特异性的。作为ColE2和ColE3复制起点的50 bp区域是迄今已鉴定和分析的原核复制子中最小的。
We have localized the regions sufficient for autonomous replication on the genomes of the colicin E2 (ColE2) and colicin E3 (ColE3) plasmids and analyzed the replication functions carried by these regions. A 1.3 kb segment of each plasmid is sufficient for autonomous replication. Plasmids carrying this segment retain the replication properties of the original plasmid. The 1.3 kb segment consists of three functional portions. Firstly, a 0.9 kg region which specifies at leat one trans-acting factor required for replication of each plasmid. Secondly, a 0.4 kb region located adjacent to ne end of the 0.9 kb region, which is required for expression of the trans-acting factor(s)and probably contains the promoter. The region across the border of these two portions of ColE2 is involved in copy number control of the plasmid. The third portion is a 50 bp region adjacent to the other end of the 0.9 kb region, which contains a cis-acting site (origin) where replication initiates in the presence of the trans-acting factor(s). The action of the trans-acting factor(s) on the origin is plasmid specific. The 50 bp regions functioning as the origins of replication of ColE2 and ColE3 are the smallest among those in prokaryotic replicons so far identified and analyzed.