Fisher E F, Feist P L, Beaucage S L, Meyers R M, Tjian R, Caruthers M H
Biochemistry. 1984 Dec 4;23(25):5938-44. doi: 10.1021/bi00320a008.
In a lytic infection of a permissive host by SV40, the large tumor antigen (T antigen), which is a product of early transcription of the SV40 A gene, has been previously shown to autoregulate its own transcription by binding to SV40 DNA. The DNA region to which T antigen binds most tightly was synthesized and subsequently introduced into the bacterial plasmid pUC8. The interaction of SV40 T antigen with the DNA duplexes, derived from both chemical synthesis and the recombinant plasmid, were examined by using nitrocellulose filter binding assays. An SV40-adenovirus hybrid protein, AD2+D2 protein, was also tested. The SV40 T antigen was found to bind more tightly than the hybrid protein. Kinetic assays demonstrated that the association rates for the two proteins with the DNA binding site were equivalent; however, once formed, the T antigen-DNA complex dissociated more slowly than the AD2+D2 protein-DNA complex.
在SV40对允许性宿主的裂解性感染中，大肿瘤抗原（T抗原）是SV40 A基因早期转录的产物，先前已表明它通过与SV40 DNA结合来自动调节自身转录。合成了T抗原结合最紧密的DNA区域，随后将其导入细菌质粒pUC8。通过硝酸纤维素滤膜结合试验检测了SV40 T抗原与化学合成和重组质粒来源的DNA双链体的相互作用。还检测了一种SV40-腺病毒杂交蛋白AD2+D2蛋白。发现SV40 T抗原比杂交蛋白结合更紧密。动力学分析表明，两种蛋白质与DNA结合位点的结合速率相当；然而，一旦形成，T抗原-DNA复合物的解离比AD2+D2蛋白-DNA复合物更慢。
