Miner J N, Hruby D E
Department of Microbiology, Oregon State University, Corvallis 97331-3804.
J Virol. 1989 Jun;63(6):2726-36. doi: 10.1128/JVI.63.6.2726-2736.1989.
To be efficiently expressed in vivo, the vaccinia virus late gene, L65, requires 5'-proximal cis-acting elements which bind a factor from infected cells. Deletion mutagenesis and vaccinia virus helper-dependent transient expression procedures were used to demonstrate that two distinct late promoter elements direct transcription from two different start sites (proximal [+1] and distal [-92]). The -128 to -112 region was essential for L65 distal promoter function, while sequences between -59 and +50 were sufficient for L65 proximal promoter function. The proximal DNA sequences interact with a protein, binding factor I (BF-I), which was isolated and partially purified from vaccinia virus-infected cells at late times postinfection. This activity is not detectable in uninfected cells or in purified virions. This factor binds specifically to two different sites within the proximal promoter, one 5' and one 3' to the transcription start site, but does not bind to the distal promoter element.
为了在体内高效表达，痘苗病毒晚期基因L65需要5'-近端顺式作用元件，该元件可结合来自受感染细胞的一种因子。采用缺失诱变和痘苗病毒辅助依赖型瞬时表达程序来证明，两个不同的晚期启动子元件从两个不同的起始位点（近端[+1]和远端[-92]）指导转录。-128至-112区域对L65远端启动子功能至关重要，而-59至+50之间的序列足以实现L65近端启动子功能。近端DNA序列与一种蛋白质结合因子I（BF-I）相互作用，该因子在感染后晚期从痘苗病毒感染的细胞中分离并部分纯化。在未感染的细胞或纯化的病毒粒子中检测不到这种活性。该因子特异性结合近端启动子内的两个不同位点，一个在转录起始位点的5'端，一个在3'端，但不结合远端启动子元件。
