Pavletich N P, Pabo C O
Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge 02139.
Science. 1993 Sep 24;261(5129):1701-7. doi: 10.1126/science.8378770.
Zinc finger proteins, of the type first discovered in transcription factor IIIA (TFIIIA), are one of the largest and most important families of DNA-binding proteins. The crystal structure of a complex containing the five Zn fingers from the human GLI oncogene and a high-affinity DNA binding site has been determined at 2.6 A resolution. Finger one does not contact the DNA. Fingers two through five bind in the major groove and wrap around the DNA, but lack the simple, strictly periodic arrangement observed in the Zif268 complex. Fingers four and five of GLI make extensive base contacts in a conserved nine base-pair region, and this section of the DNA has a conformation intermediate between B-DNA and A-DNA. Analyzing the GLI complex and comparing it with Zif268 offers new perspectives on Zn finger-DNA recognition.
锌指蛋白是最早在转录因子IIIA（TFIIIA）中发现的一类蛋白，是最大且最重要的DNA结合蛋白家族之一。已确定了一个包含来自人类GLI癌基因的五个锌指和一个高亲和力DNA结合位点的复合物的晶体结构，分辨率为2.6埃。第一个锌指不与DNA接触。第二至第五个锌指在大沟中结合并环绕DNA，但缺乏在Zif268复合物中观察到的简单、严格的周期性排列。GLI的第四和第五个锌指在一个保守的九个碱基对区域与碱基广泛接触，并且该段DNA具有介于B-DNA和A-DNA之间的构象。分析GLI复合物并将其与Zif268进行比较，为锌指与DNA的识别提供了新的视角。
