Kouzarides T, Packham G, Cook A, Farrell P J
Department of Pathology, University of Cambridge Addenbrooke's Hospital, London, UK.
Oncogene. 1991 Feb;6(2):195-204.
The EBV transactivator protein BZLF1 can bind many sites in the EBV genome, most of which have homology to a consensus AP-1 site, the binding site for the fos/jun family of transcription factors. Here we present evidence that BZLF1 can also recognise the binding site for the CCAAT/enhancer binding protein C/EBP and that a BZLF1 binding site within the BZLF1 promoter is recognised by the C/EBP protein. Analysis of the BZLF1 DNA binding domain suggests that the BZLF1 protein binds to DNA as a dimer using sequences adjacent to a basic DNA binding motif. The BZLF1 dimerisation domain does not have a heptad repeat of leucine residues common to leucine zipper proteins but does have characteristics of a coiled coil structure, as judged by site directed mutagenesis. We therefore propose that the dimerisation domain of BZLF1 is structurally related to the coiled coil structure of leucine zippers but lacks the highly conserved leucine repeat. We show that the PZLF1 dimerisation domain has residues in common with the C/EBP leucine zipper and discuss the possible implications of this relationship.
EB病毒反式激活蛋白BZLF1可结合EB病毒基因组中的多个位点，其中大多数与共有AP-1位点具有同源性，AP-1位点是转录因子fos/jun家族的结合位点。在此，我们提供证据表明，BZLF1还能识别CCAAT/增强子结合蛋白C/EBP的结合位点，并且C/EBP蛋白可识别BZLF1启动子内的一个BZLF1结合位点。对BZLF1 DNA结合结构域的分析表明，BZLF1蛋白以二聚体形式结合DNA，其结合序列紧邻一个基本DNA结合基序。BZLF1二聚化结构域没有亮氨酸拉链蛋白常见的亮氨酸残基七肽重复序列，但通过定点诱变判断，它具有卷曲螺旋结构的特征。因此，我们提出BZLF1的二聚化结构域在结构上与亮氨酸拉链的卷曲螺旋结构相关，但缺乏高度保守的亮氨酸重复序列。我们发现PZLF1二聚化结构域与C/EBP亮氨酸拉链有共同的残基，并讨论了这种关系的可能影响。
