Okuley Susan, Call Mindy, Mitchell Tara, Hu Bugen, Woodworth Mary E
Department of Microbiology, Miami University, Oxford, Ohio 45056, USA.
J Virol. 2003 Oct;77(19):10651-7. doi: 10.1128/jvi.77.19.10651-10657.2003.
T-antigen-induced DNA distortion was studied in a series of simian virus 40 (SV40) plasmid constructs whose relative replication efficiency ranges from 0.2 to 36. Bending was detected in the wild-type SV40 regulatory region consisting of three copies of the GC-rich 21-bp repeat but not in constructs with only one or two copies of the 21-bp repeat. In a construct with enhanced replication efficiency, bending occurred in a 69-bp cellular sequence located upstream of a single copy of the 21-bp repeat. Bending occurred both upstream of ori and in the three 21-bp repeats located downstream of ori in a construct with reduced replication efficiency. In a construct with no 21-bp repeats, DNA distortion occurred downstream of ori. The results indicate that SV40 DNA replication is enhanced when the structure of the regulatory region allows the DNA to form a bent structure upstream of the initial movement of the replication fork.
在一系列猿猴病毒40（SV40）质粒构建体中研究了T抗原诱导的DNA扭曲，这些构建体的相对复制效率范围为0.2至36。在由富含GC的21碱基重复序列的三个拷贝组成的野生型SV40调控区域中检测到弯曲，但在仅具有一个或两个21碱基重复序列拷贝的构建体中未检测到弯曲。在一个复制效率增强的构建体中，弯曲发生在位于21碱基重复序列单拷贝上游的69碱基细胞序列中。在一个复制效率降低的构建体中，弯曲发生在ori上游以及位于ori下游的三个21碱基重复序列中。在一个没有21碱基重复序列的构建体中，DNA扭曲发生在ori下游。结果表明，当调控区域的结构允许DNA在复制叉初始移动上游形成弯曲结构时，SV40 DNA复制会增强。
