Yamasaki Kazuhiko, Kigawa Takanori, Inoue Makoto, Yamasaki Tomoko, Yabuki Takashi, Aoki Masaaki, Seki Eiko, Matsuda Takayoshi, Tomo Yasuko, Terada Takaho, Shirouzu Mikako, Tanaka Akiko, Seki Motoaki, Shinozaki Kazuo, Yokoyama Shigeyuki
Age Dimension Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8566, Japan.
J Mol Biol. 2005 Apr 29;348(2):253-64. doi: 10.1016/j.jmb.2005.02.065.
Ethylene-insensitive3 (EIN3) and EIN3-like (EIL) proteins are essential transcription factors in the ethylene signaling of higher plants. The EIN3/EIL proteins bind to the promoter regions of the downstream genes and regulate their expression. The location of the DNA-binding domain (DBD) in the primary structure was unclear, since the proteins show no sequence similarity to other known DBDs. Here, we identify the major DBD of an EIN3/EIL protein, Arabidopsis thaliana EIL3, containing a key mutational site for DNA binding and signaling (ein3-3 site), and determine its solution structure by NMR spectroscopy. The structure consists of five alpha-helices, possessing a novel fold dissimilar to known DBD structures. By a chemical-shift perturbation analysis, a region including the ein3-3 site is suggested to be involved in DNA binding.
乙烯不敏感3（EIN3）和乙烯不敏感3样（EIL）蛋白是高等植物乙烯信号传导中必不可少的转录因子。EIN3/EIL蛋白与下游基因的启动子区域结合并调节其表达。由于这些蛋白与其他已知的DNA结合结构域（DBD）没有序列相似性，其一级结构中DNA结合结构域（DBD）的位置尚不清楚。在此，我们鉴定了一种EIN3/EIL蛋白——拟南芥EIL3的主要DBD，它包含一个DNA结合和信号传导的关键突变位点（ein3-3位点），并通过核磁共振光谱确定了其溶液结构。该结构由五个α螺旋组成，具有与已知DBD结构不同的新颖折叠。通过化学位移扰动分析，一个包括ein3-3位点的区域被认为参与DNA结合。
