Characterization of the DNA-binding domain of the bovine papillomavirus replication initiator E1
Characterization of the DNA-binding domain of the bovine papillomavirus replication initiator E1
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DOI：
10.1128/jvi.72.4.2567-2576.1998
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发表时间：
1998-04-01
影响因子：
5.4
通讯作者：
Stenlund, A
中科院分区：
文献类型：
--
作者：
Chen, G;Stenlund, A
牛乳头瘤病毒复制起始蛋白 E1 是复制起点 (ori)；病毒 DNA 复制绝对需要的结合蛋白。在病毒转录因子 E2 存在的情况下，E1 与 ori 结合并启动 DNA 复制。为了了解 E1 起始子如何识别 ori 以及 E2 如何在此过程中提供协助，我们表达并纯化了一个 166 个氨基酸片段，该片段对应于最小的 E1 DNA 结合域 (DBD)。使用该蛋白质进行的 DNA 结合研究表明，E1 DBD 可以多种形式与回文 E1 结合位点结合，但主要形式是两个单体的结合，每个单体识别 E1 回文的一个半位点。这让人想起 T 抗原 DBD 与 SV40 ori 的结合，有趣的是，E1 结合位点的排列与 SV40 ori 中 T 抗原结合位点的排列显示出惊人的相似性，尽管识别序列不相关。 E1 DBD能够与E2协同交互；然而，E2 DBD 而不是 E2 激活域介导这种相互作用。此外，E2 DBD 通过与一个 E1 单体协同结合，刺激 E1 DBD 的两个单体与 ori 的结合。最后，我们表明我们关于 E1 DBD 的 DNA 结合特性的结果可以扩展到全长 E1。
The bovine papillomavirus replication initiator protein E1 is an origin of replication (ori);binding protein absolutely required for viral DNA replication. In the presence of the viral transcription factor E2, E1 binds to the ori and initiates DNA replication. To understand how the E1 initiator recognizes the ori and how E2 assists in this process, we have expressed and purified a 166-amino-acid fragment, which corresponds to the minimal E1 DNA-binding domain (DBD). DNA binding studies using this protein demonstrate that the E1 DBD can bind to the palindromic E1 binding site in several forms but that binding of two monomers, each recognizing one half-site of the E1 palindrome, is the predominant form. This is reminiscent of the binding of the T-antigen DBD to the SV40 ori, and interestingly, the arrangement of E1 binding sites shows striking similarities to the arrangement of T-antigen binding sites in the SV40 ori even though the recognition sequences are unrelated. The E1 DBD is capable of interacting cooperatively with E2; however, the E2 DBD and not the E2 activation domain mediates this interaction. Furthermore, the E2 DBD stimulates binding of two monomers of the E1 DBD to the ori by binding cooperatively with one E1 monomer. Finally, we show that our results concerning the DNA-binding properties of the E1 DBD can be extended to full-length E1.