Benada O, Navrátil O
Institute of Microbiology, Czechoslovak Academy of Sciences, Prague.
Folia Microbiol (Praha). 1992;37(5):347-52. doi: 10.1007/BF02815660.
The plasmids pON5300 and pON5304, nonconjugative variants of the plasmid R1drd-19Km, were analyzed by electron microscopy. It was found by heteroduplex mapping that a 1.4 kb DNA segment was inserted into EcoRI E fragment of both plasmids, where some tra-genes and oriT are localized. Although this DNA segment was mapped to the same region its orientation was different in each of the two plasmids. The inserted DNA segment was identified as an IS10R sequence on the basis of analysis of self-annealed molecules of pON5304 and their cleavage with EcoRV restriction enzyme. These methods enable us not only to map IS10R sequences on 87 kb pON5300 and 65 kb pON5304 molecules, respectively, but also to define their orientation.
通过电子显微镜对质粒R1drd - 19Km的非接合变体pON5300和pON5304进行了分析。通过异源双链体图谱分析发现，在这两个质粒的EcoRI E片段中插入了一个1.4 kb的DNA片段，一些转移基因和转移起始位点（oriT）定位于此。尽管该DNA片段被定位到相同区域，但在两个质粒中其方向不同。基于对pON5304自身退火分子及其用EcoRV限制酶切割的分析，将插入的DNA片段鉴定为IS10R序列。这些方法不仅使我们能够分别在87 kb的pON5300分子和65 kb的pON5304分子上绘制IS10R序列图谱，还能确定它们的方向。
