Ohtsubo H, Ohtsubo E
Proc Natl Acad Sci U S A. 1978 Feb;75(2):615-9. doi: 10.1073/pnas.75.2.615.
PSM2, PSM1, and PSM15 are small plasmids derived from R100 by spontaneous deletions at either end of the insertion sequence IS1. These plasmids were used to identify regions neighboring IS1 as well as the IS1 DNA itself, by cleavage with EcoR1, HindIII, Hae III, Hpa II, Hha I, Hinf, and AIu I. The nucleotide sequencing results demonstrate that IS1 contains 768 bases. About 30 bases at the ends of IS1 were found to be repeated in an inverted order. The deletions occurring at the ends of IS1 were found to be due to illegitimate recombination. The hypothesis that RNA polymerase could play an important role in such recombination phenomena is discussed based on the nucleotide sequences surrounding the recombinational hot spots.
PSM2、PSM1和PSM15是通过插入序列IS1两端的自发缺失从R100衍生而来的小质粒。这些质粒用于通过用EcoR1、HindIII、Hae III、Hpa II、Hha I、Hinf和AIu I切割来鉴定与IS1相邻的区域以及IS1 DNA本身。核苷酸测序结果表明IS1含有768个碱基。发现IS1末端约30个碱基以反向顺序重复。发现发生在IS1末端的缺失是由于非法重组。基于重组热点周围的核苷酸序列，讨论了RNA聚合酶可能在这种重组现象中起重要作用的假说。
