Szeverényi I, Bodoky T, Olasz F
Institute for Molecular Genetics, Agricultural Biotechnology Center Gödöllö, Hungary.
Mol Gen Genet. 1996 Jun 12;251(3):281-9. doi: 10.1007/BF02172518.
We have isolated and characterized a dimer derivative of the extensively studied Escherichia coli insertion sequence IS2. The dimer structure--called (IS2)2--consists of two IS2 elements arranged as a direct repeat, separated by 1 bp. The junction between the (IS2)2 dimer and target sequences is located at various positions in independent isolates; however, one position was preferred. The transposition of (IS2)2 into a target plasmid resulted in cointegrate-type structures. The transposition frequency of the (IS2)2 dimer itself was significantly higher than that of the isogenic monomer IS2 insertion. The poor stability and high activity of (IS2)2 indicates that this is an active transposition intermediate. The mode of transposition of (IS2)2 is analogous to the joined dimer model described in the case of (IS21)2 and (IS30)2.
我们已经分离并鉴定了经过广泛研究的大肠杆菌插入序列IS2的二聚体衍生物。这种二聚体结构——称为(IS2)2——由两个作为同向重复排列的IS2元件组成，它们之间相隔1个碱基对。(IS2)2二聚体与靶序列之间的连接点在独立分离株中的位置各不相同；然而，有一个位置是更受青睐的。(IS2)2转座到靶质粒中会产生共整合型结构。(IS2)2二聚体自身的转座频率显著高于同基因单体IS2插入的频率。(IS2)2的稳定性差和活性高表明它是一种活跃的转座中间体。(IS2)2的转座模式类似于在(IS21)2和(IS30)2的情况中所描述的连接二聚体模型。
