Pavletich N P, Pabo C O
Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Science. 1991 May 10;252(5007):809-17. doi: 10.1126/science.2028256.
The zinc finger DNA-binding motif occurs in many proteins that regulate eukaryotic gene expression. The crystal structure of a complex containing the three zinc fingers from Zif268 (a mouse immediate early protein) and a consensus DNA-binding site has been determined at 2.1 angstroms resolution and refined to a crystallographic R factor of 18.2 percent. In this complex, the zinc fingers bind in the major groove of B-DNA and wrap part way around the double helix. Each finger has a similar relation to the DNA and makes its primary contacts in a three-base pair subsite. Residues from the amino-terminal portion of an alpha helix contact the bases, and most of the contracts are made with the guanine-rich strand of the DNA. This structure provides a framework for understanding how zinc fingers recognize DNA and suggests that this motif may provide a useful basis for the design of novel DNA-binding proteins.
锌指DNA结合基序存在于许多调节真核基因表达的蛋白质中。包含来自Zif268（一种小鼠即早蛋白）的三个锌指和一个共有DNA结合位点的复合物的晶体结构已在2.1埃分辨率下确定，并精修至晶体学R因子为18.2%。在该复合物中，锌指结合在B-DNA的大沟中，并部分环绕双螺旋。每个锌指与DNA具有相似的关系，并在一个三碱基对亚位点进行主要接触。α螺旋氨基末端部分的残基与碱基接触，且大多数接触是与DNA富含鸟嘌呤的链进行的。这种结构为理解锌指如何识别DNA提供了一个框架，并表明该基序可能为设计新型DNA结合蛋白提供有用的基础。
