Ward P, Berns K I
Hearst Microbiology Research Center, Department of Microbiology, Cornell University Medical College, New York, NY 10021.
J Mol Biol. 1991 Apr 20;218(4):791-804. doi: 10.1016/0022-2836(91)90267-a.
In an in vitro simian virus 40 (SV40) DNA replication assay, we have observed excision of a hybrid adeno-associated virus (AAV)/SV40 insert from a plasmid construct. The excision was dependent on the presence of the palindromic AAV terminal repeat and greatly enhanced by the addition of the SV40 T antigen to the reaction. Analysis of the excision product supports a model in which the palindromic terminal sequences of AAV form a cruciform structure (equivalent to a Holliday recombination intermediate), which is cleaved and resealed so that the excision products are linear duplex pBR322 and linear duplex AAV/SV40 insert. Both the excised linear duplex pBR322 and the excised linear duplex AAV/SV40 insert have each terminus covalently crosslinked by one copy of the palindromic region of the AAV terminal repeat region folded on itself. The excision process may be a model system for cellular homologous recombination. The process as observed was either concomitant with or subsequent to DNA replication.
在一项体外猿猴病毒40（SV40）DNA复制试验中，我们观察到从一个质粒构建体中切除了一个杂交腺相关病毒（AAV）/SV40插入片段。切除依赖于回文AAV末端重复序列的存在，并且通过向反应中添加SV40 T抗原而大大增强。对切除产物的分析支持一种模型，其中AAV的回文末端序列形成十字形结构（等同于霍利迪重组中间体），该结构被切割并重新封闭，使得切除产物为线性双链pBR322和线性双链AAV/SV40插入片段。切除的线性双链pBR322和切除的线性双链AAV/SV40插入片段的每个末端都通过自身折叠的AAV末端重复区域回文区域的一个拷贝共价交联。切除过程可能是细胞同源重组的一个模型系统。观察到的过程与DNA复制同时发生或在DNA复制之后。
