Jost C A, Ginsberg D, Kaelin W G
Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Virology. 1996 Jun 1;220(1):78-90. doi: 10.1006/viro.1996.0288.
E2F DNA-binding activity in vivo is due to heterodimer formation between members of the E2F and DP transcription factor families. The ability of these heterodimers to serve as transcriptional regulators is modulated by complex formation with additional proteins such as the products of the retinoblastoma gene and the adenovirus E4 ORF 6/7. Each of the E2F family members cloned to date contains a highly conserved region of unknown function, termed the marked box, which lies between their DNA binding and transactivation domains. Mutational analysis showed that the marked box contributed to the recognition of E2F family members by the E4 ORF 6/7 protein in vitro and in vivo.
E2F在体内的DNA结合活性归因于E2F转录因子家族成员与DP转录因子家族成员之间形成的异源二聚体。这些异源二聚体作为转录调节因子的能力受到与其他蛋白质（如视网膜母细胞瘤基因产物和腺病毒E4 ORF 6/7）形成复合物的调节。迄今为止克隆的每个E2F家族成员都包含一个功能未知的高度保守区域，称为标记框，它位于其DNA结合域和反式激活域之间。突变分析表明，标记框在体外和体内有助于E4 ORF 6/7蛋白识别E2F家族成员。
