Doroshenko V G, Danilevich V N, Karataev G I, Livshits V A
Mol Biol (Mosk). 1988 May-Jun;22(3):645-58.
Transposon Tn2555 was isolated from a clinical E. coli strain carries the genes for sucrose utilization. Previously it was shown that Tn2555 is very unstable and undergoes structural rearrangements with a high frequency. Several deletion derivatives of Tn2555 and one with an inversion of the internal segment were found. They form the Tn2555 transposon family. This paper describes further structural and functional analysis of Tn2555. In the course of the experiments on pBR325 (Mob-) mobilization by conjugative RP4 derivatives, containing Tn2555 family elements, it was found, that all of them induce cointegrate formation. Some of these cointegrates were able to dissociate in rec+ and recA E. coli cells. Restriction endonuclease analysis of the resulting plasmids have shown, that among them were the end products of the Tn2555 transposition from RP4 to pBR325. Besides, the pBR325 derivatives, containing a discrete DNA segment of approximately 800 b.p., originating from Tn2555, were found. The segment can transpose from pBR325 to RP4 indicating that it is an insertion sequence. This new IS-element was designated IS286. The size and the genetic properties of IS286 resemble those of the IS1 element. However restriction analysis and Southern hybridization data show no significant homology between IS286 and IS1. It was found that the Tn2555 family elements are flanked by directly repeated IS286. One of them (Tn2555.3) contains an additional copy of IS286 in its internal region.
转座子Tn2555是从一株携带蔗糖利用基因的临床大肠杆菌菌株中分离出来的。此前已表明，Tn2555非常不稳定，会高频发生结构重排。发现了Tn2555的几种缺失衍生物以及一种内部片段发生倒位的衍生物。它们构成了Tn2555转座子家族。本文描述了对Tn2555的进一步结构和功能分析。在含有Tn2555家族元件的接合型RP4衍生物对pBR325（Mob-）进行动员的实验过程中，发现它们都能诱导共整合体形成。其中一些共整合体能够在rec+和recA大肠杆菌细胞中解离。对所得质粒的限制性内切酶分析表明，其中有Tn2555从RP4转座到pBR325的终产物。此外，还发现了含有一段约800个碱基对、源自Tn2555的离散DNA片段的pBR325衍生物。该片段可从pBR325转座到RP4，表明它是一个插入序列。这个新的IS元件被命名为IS286。IS286的大小和遗传特性与IS1元件相似。然而，限制性分析和Southern杂交数据显示IS286与IS1之间没有明显的同源性。发现Tn2555家族元件两侧是直接重复的IS286。其中一个（Tn2555.3）在其内部区域含有IS286的一个额外拷贝。
