Reece R J, Ptashne M
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138.
Science. 1993 Aug 13;261(5123):909-11. doi: 10.1126/science.8346441.
Related DNA binding proteins often recognize similar DNA sites but can distinguish among them with the use of different protein-DNA contacts. Here, it is shown that members of the C6 zinc cluster family of yeast transcriptional activators distinguish related DNA sites by a different mechanism. The DNA binding site for each of these proteins contains identical nucleotide triplets (CGG ... CCG) but differs in the spacings between the triplets. It is shown that zinc clusters of these proteins work interchangeably to recognize the conserved triplets and that the region 19 amino acids to the carboxyl-terminal side of the zinc cluster, comprising the linker and the beginning of a dimerization element as inferred from the GAL4 crystal structure, directs the protein to its preferred site.
相关的DNA结合蛋白通常识别相似的DNA位点，但可通过不同的蛋白质-DNA相互作用来区分它们。在此研究中发现，酵母转录激活因子C6锌簇家族的成员通过一种不同的机制区分相关的DNA位点。这些蛋白质各自的DNA结合位点都含有相同的核苷酸三联体（CGG...CCG），但三联体之间的间距不同。研究表明，这些蛋白质的锌簇可互换作用以识别保守的三联体，并且从GAL4晶体结构推断，锌簇羧基末端一侧19个氨基酸的区域，包括连接子和二聚化元件的起始部分，将蛋白质导向其偏好的位点。
