Mechanism of intramolecular recyclization and deletion formation following transformation of Escherichia coli with linearized plasmid DNA.
Mechanism of intramolecular recyclization and deletion formation following transformation of Escherichia coli with linearized plasmid DNA.
复制标题
DOI：
10.1093/nar/14.22.8919
复制
发表时间：
1986-11
影响因子：
14.9
通讯作者：
E. C. Conley;V. Saunders;V. Jackson;J. Saunders
中科院分区：
文献类型：
--
作者：
E. C. Conley;V. Saunders;V. Jackson;J. Saunders
通过DNA测序确定了用线形pBR322 DNA转化recA+或recA-E.coli后获得的多个I型(小于单体)质粒缺失体的缺失终点。在单向和双向缺失中，回收点通常由线性化的pBR322分子的每个臂上存在的4到10个核苷酸的直接重复序列之间的重组来表征。通常，涉及重组再循环的短片段不间断同源性被嵌入到相对非同源性区域。提出了一个预测线性质粒分子两端序列匹配概率的模型。有人认为，线形质粒分子暴露的末端的胞外溶解处理为随后的重组回收和缺失产生底物。宿主重组和修复功能在线性DNA分子再循环中的活性解释了在基因克隆过程中获得的许多异常重组DNA结构的产生。
The deletion end-points of a number of type I (less than monomeric) plasmid deletants obtained by transforming recA+ or recA- E. coli with linear pBR322 DNA were determined by DNA sequencing. In both monodirectional and bidirectional deletions the recyclization point was normally characterized by recombination between directly repeated sequences of between 4 and 10 bp present on each arm of the linearized pBR322 molecule. Frequently, short tracts of uninterrupted homology involved in recombinational recircularization were embedded in regions of relative non-homology. A model predicting the probability of matching sequences in either end of a linear plasmid molecule is presented. It is proposed that exonucleolytic processing of the exposed termini of linear plasmid molecules generates substrates for subsequent recombinational recyclization and deletion. The activity of host recombination and repair functions in recircularizing linear DNA molecules explains the generation of many of the aberrant recombinant DNA constructs obtained during gene cloning procedures.