ISOLATION OF CDNA-ENCODING TRANSCRIPTION FACTOR SP1 AND FUNCTIONAL-ANALYSIS OF THE DNA-BINDING DOMAIN
ISOLATION OF CDNA-ENCODING TRANSCRIPTION FACTOR SP1 AND FUNCTIONAL-ANALYSIS OF THE DNA-BINDING DOMAIN
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DOI：
10.1016/0092-8674(87)90594-0
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发表时间：
1987-12-24
期刊：
影响因子：
64.5
通讯作者：
TIJIAN, R
中科院分区：
文献类型：
--
作者：
KADONAGA, JT;CARNER, KR;TIJIAN, R
转录因子Sp1是一种存在于哺乳动物细胞中的蛋白质，其结合GC盒启动子元件并选择性地激活来自含有功能识别位点的基因的mRNA合成。我们已经分离出一个cDNA，编码696个C-末端氨基酸残基的人Sp1。通过在E.在大肠杆菌中，我们将DNA结合活性定位于C-末端168个氨基酸残基。在该区域，Sp1具有三个连续的Zn（II）指基序，据信它们是与DNA相互作用的金属蛋白结构。我们已经发现，纯化的Sp1需要Zn（II）的序列特异性结合到DNA。因此，很可能Sp1通过Zn（II）指的结合与DNA相互作用。为了便于鉴定DNA结合缺陷的SP1突变变体，我们还设计了一种细菌菌落试验来检测SP1与DNA的结合。
Transcription factor Sp1 is a protein present in mammalian cells that binds to GC box promoter elements and selectively activates mRNA synthesis from genes that contain functional recognition sites. We have isolated a cDNA that encodes the 696 C-terminal amino acid residues of human Sp1. By expression of truncated fragments of SP1 in E. coli, we have localized the DNA binding activity to the C-terminal 168 amino acid residues. In this region, Sp1 has three contiguous Zn(II) finger motifs, which are believed to be metalloprotein structures that interact with DNA. We have found that purified Sp1 requires Zn(II) for sequence-specific binding to DNA. Thus, it is likely that Sp1 interacts with DNA by binding of the Zn(II) fingers. To facilitate the identification of mutant variants of SP1 that are defective in DNA binding, we have also devised a bacterial colony assay for detection of Sp1 binding to DNA.