Bovine papilloma virus (BPV)-encoded E2 protein enhances binding of E1 protein to the BPV replication origin.
Bovine papilloma virus (BPV)-encoded E2 protein enhances binding of E1 protein to the BPV replication origin.
复制标题
牛乳头瘤病毒 (BPV) 编码的 E2 蛋白增强 E1 蛋白与 BPV 复制起点的结合。
DOI：
10.1073/pnas.90.7.2865
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发表时间：
1993
影响因子：
11.1
通讯作者：
Hurwitz,J
中科院分区：
文献类型：
--
作者：
Seo,YS;Müller,F;Lusky,M;Gibbs,E;Kim,HY;Phillips,B;Hurwitz,J
牛乳头瘤病毒（BPV）DNA在体内的复制需要两种病毒编码的蛋白质，E1和E2，而所有其他蛋白质都来自宿主。我们先前描述了E1蛋白的分离，并表明它包含BPV DNA复制所需的多种功能。BPV转录因子E2在体外刺激BPV DNA复制。在这里，我们提出的结果，占E2蛋白的作用。E1蛋白选择性结合BPV最小复制起点。这一过程需要MgCl 2和ATP来达到最大效率。E1蛋白还催化BPV来源依赖的DNA解旋反应。在这份报告中，我们表明，在低水平的E1蛋白，起源结合可以刺激高达40倍的E2蛋白，提供的DNA含有E2结合位点。与此结果一致，E2蛋白刺激E1催化的起始特异性解旋反应，但对非特异性E1催化的解旋酶活性没有影响。在没有E2结合位点的情况下，与E1蛋白的起始依赖性结合和解旋反应均不受E2蛋白的影响。这些结果表明，E2通过DNA-蛋白和蛋白-蛋白相互作用增强E1与BPV起点的结合，参与BPV DNA复制的启动。
The replication of bovine papilloma virus (BPV) DNA in vivo requires two viral-encoded proteins, E1 and E2, while all other proteins are derived from the host. We described previously the isolation of the E1 protein and showed that it contains multiple functions required for BPV DNA replication. The BPV transcription factor E2 was shown by others to stimulate BPV DNA replication in vitro. Here, we present results that account for the role of the E2 protein. The E1 protein bound selectively to the BPV minimal origin of replication. This process required MgCl2 and ATP for maximal efficiency. The E1 protein also catalyzed a BPV origin-dependent DNA unwinding reaction. In this report, we show that at low levels of E1 protein, origin binding could be stimulated up to 40-fold by the E2 protein, provided that the DNA contained an E2 binding site. Consistent with this result, the E2 protein stimulated the origin-specific unwinding reaction catalyzed by E1, but it had no effect on the nonspecific E1-catalyzed helicase activity. In the absence of an E2 binding site, both origin-dependent binding and unwinding reactions with the E1 protein were unaffected by the E2 protein. These results suggest that E2 participates in the initiation of BPV DNA replication by enhancing E1 binding to the BPV origin via DNA-protein and protein-protein interactions.