Peters J E, Craig N L
Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Mol Cell. 2000 Sep;6(3):573-82. doi: 10.1016/s1097-2765(00)00056-3.
We report that the bacterial transposon Tn7 can preferentially transpose into regions where chromosomal DNA replication terminates. DNA double-strand breaks are associated with the termination of chromosomal replication; therefore, we directly tested the effect of DNA breaks on Tn7 transposition. When DNA double-strand breaks are induced at specific sites in the chromosome, Tn7 transposition is stimulated and insertions are directed proximal to the induced break. The targeting preference for the terminus of replication and DNA double-strand breaks is dependent on the Tn7-encoded protein TnsE. The results presented in this study could also explain the previous observation that Tn7 is attracted to events associated with conjugal DNA replication during plasmid DNA transfer.
我们报告称，细菌转座子Tn7能够优先转座到染色体DNA复制终止的区域。DNA双链断裂与染色体复制的终止相关；因此，我们直接测试了DNA断裂对Tn7转座的影响。当在染色体的特定位点诱导DNA双链断裂时，Tn7转座受到刺激，并且插入发生在诱导断裂近端。对复制终点和DNA双链断裂的靶向偏好取决于Tn7编码的蛋白TnsE。本研究中呈现的结果也可以解释之前的观察结果，即Tn7在质粒DNA转移过程中被与接合DNA复制相关的事件所吸引。
