Wilson V G, Ludes-Meyers J
Department of Medical Microbiology and Immunology, Texas A&M University, College Station 77843.
J Virol. 1991 Oct;65(10):5314-22. doi: 10.1128/JVI.65.10.5314-5322.1991.
The E1 open reading frame of bovine papillomavirus (BPV) was expressed as a RecA-E1 fusion protein in Escherichia coli. The bacterially expressed RecA-E1 protein exhibited sequence-specific DNA binding activity; strong binding to the region from nucleotides 7819 to 93 on the BPV genome (designated region A) and weak binding to the adjacent region from nucleotides 7457 to 7818 (region B) were observed. The interaction between the BPV-derived RecA-E1 protein and region A appeared to be highly specific for BPV DNA, as no comparable binding was detected with heterologous papillomavirus DNAs. Binding to region A was eliminated by digestion of region A at the unique HpaI site, which suggests that the RecA-E1 binding site(s) was at or near the HpaI recognition sequence. Binding to region B but not region A was observed when nuclear extracts from ID13 cells were used as a source of E1 proteins. The absence of region A binding by ID13 extracts may reflect a negative regulation of E1 DNA binding activity.
牛乳头瘤病毒（BPV）的E1开放阅读框在大肠杆菌中表达为RecA-E1融合蛋白。细菌表达的RecA-E1蛋白表现出序列特异性DNA结合活性；观察到它与BPV基因组上从核苷酸7819到93的区域（指定为区域A）有强结合，而与相邻的从核苷酸7457到7818的区域（区域B）有弱结合。BPV来源的RecA-E1蛋白与区域A之间的相互作用似乎对BPV DNA具有高度特异性，因为未检测到与异源乳头瘤病毒DNA有类似的结合。通过在独特的HpaI位点消化区域A可消除与区域A的结合，这表明RecA-E1结合位点位于HpaI识别序列处或其附近。当使用ID13细胞的核提取物作为E1蛋白来源时，观察到与区域B而非区域A的结合。ID13提取物缺乏与区域A的结合可能反映了E1 DNA结合活性的负调控。
