A NOVEL DNA-BINDING PROTEIN WITH HOMOLOGY TO MYB ONCOPROTEINS CONTAINING ONLY ONE REPEAT CAN FUNCTION AS A TRANSCRIPTIONAL ACTIVATOR
A NOVEL DNA-BINDING PROTEIN WITH HOMOLOGY TO MYB ONCOPROTEINS CONTAINING ONLY ONE REPEAT CAN FUNCTION AS A TRANSCRIPTIONAL ACTIVATOR
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DOI：
10.1002/j.1460-2075.1994.tb06873.x
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发表时间：
1994-11-15
期刊：
影响因子：
11.4
通讯作者：
WILLMITZER, L
中科院分区：
文献类型：
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作者：
BARANOWSKIJ, N;FROHBERG, C;WILLMITZER, L
以CaMV 35S启动子域A为探针，通过西南基因筛选，从马铃薯cDNA表达文库中分离到一个编码myb相关蛋白的cDNA克隆MybSt1。序列比较显示一个小区域与高度保守的c-myb原癌基因的DNA结合域有一定的同源性，由三个不完全重复组成。MybSt1蛋白的Myb基序与目前所描述的植物Myb DNA结合域不同。与已知的植物Myb蛋白相比，mybSt1的DNA结合活性需要两个重复序列，而克隆mybSt1只包含一个重复序列。然而，myb相关蛋白MybSt1能够以序列特异性的方式与DNA结合。除了Myb-like区域外，蛋白MybSt1在其中心区域含有一个酸性片段，在c端附近含有一个富含脯氨酸的区域。应用随机结合位点选择技术，鉴定出MybSt1的高亲和力DNA结合位点，共享核心基序GGATA。在植物原生质体的瞬时表达实验中，获得了myb克隆作为转录激活因子的明确证据。
A cDNA clone encoding a novel Myb-related protein, designated MybSt1, was isolated from a potato cDNA expression library by South Western screening using the CaMV 35S promoter domain A as a probe. Sequence comparison shows a small region with some homology to the highly conserved DNA binding domain of the c-myb proto-oncogene consisting of three imperfect repeats. The Myb motif of the MybSt1 protein is distinct from the plant Myb DNA binding domain described so far. In contrast to the known plant Myb proteins, with two repeats required for the DNA binding activity, the clone mybSt1 contains only one such repeat. Nevertheless, the Myb-related protein MybSt1 is able to bind to DNA in a sequence-specific manner. In addition to the Myb-like region, the protein MybSt1 contains an acidic segment in its central region as well as a proline-rich region near the C-terminus. Applying the random binding site selection technique, high-affinity DNA binding sites for MybSt1 were identified, sharing the core motif GGATA. In transient expression assays using plant protoplasts, clear evidence was obtained for this myb clone functioning as a transcriptional activator.