Ryder K, Vakalopoulou E, Mertz R, Mastrangelo I, Hough P, Tegtmeyer P, Fanning E
Cell. 1985 Sep;42(2):539-48. doi: 10.1016/0092-8674(85)90111-4.
Three sequence components direct high affinity binding of dimeric SV40 T antigen to SV40 origin region I. Two signals are encoded by two directly repeated 5'-GAGGC-3' pentanucleotides. Approximately equal contributions to binding stability are made by each pentanucleotide, and both spacing and orientation of the pentanucleotides are important for binding affinity. The third vital component is contained in a 5'-TTTTTTG-3' spacer sequence that separates the pentanucleotides. Sequence-specific features of the spacer stabilize binding to the adjacent pentanucleotides. The asymmetry of the spacer suggests that a novel binding mechanism is involved. Because the alignment of T antigen on mutant and wild-type DNAs is similar, we propose that any two of the three sequence signals are sufficient to determine the unique arrangement of a bound protein dimer.
三个序列元件指导二聚体SV40 T抗原与SV40起始区域I的高亲和力结合。两个信号由两个直接重复的5'-GAGGC-3'五核苷酸编码。每个五核苷酸对结合稳定性的贡献大致相等，五核苷酸的间距和方向对结合亲和力都很重要。第三个关键元件包含在分隔五核苷酸的5'-TTTTTTG-3'间隔序列中。间隔序列的序列特异性特征稳定了与相邻五核苷酸的结合。间隔序列的不对称性表明涉及一种新的结合机制。由于T抗原在突变体和野生型DNA上的排列相似，我们提出三个序列信号中的任何两个都足以确定结合的蛋白质二聚体的独特排列。
