Slupsky C M, Gentile L N, Donaldson L W, Mackereth C D, Seidel J J, Graves B J, McIntosh L P
Department of Biochemistry and Molecular Biology and Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z3.
Proc Natl Acad Sci U S A. 1998 Oct 13;95(21):12129-34. doi: 10.1073/pnas.95.21.12129.
The Pointed (PNT) domain and an adjacent mitogen-activated protein (MAP) kinase phosphorylation site are defined by sequence conservation among a subset of ets transcription factors and are implicated in two regulatory strategies, protein interactions and posttranslational modifications, respectively. By using NMR, we have determined the structure of a 110-residue fragment of murine Ets-1 that includes the PNT domain and MAP kinase site. The Ets-1 PNT domain forms a monomeric five-helix bundle. The architecture is distinct from that of any known DNA- or protein-binding module, including the helix-loop-helix fold proposed for the PNT domain of the ets protein TEL. The MAP kinase site is in a highly flexible region of both the unphosphorylated and phosphorylated forms of the Ets-1 fragment. Phosphorylation alters neither the structure nor monomeric state of the PNT domain. These results suggest that the Ets-1 PNT domain functions in heterotypic protein interactions and support the possibility that target recognition is coupled to structuring of the MAP kinase site.
尖状（PNT）结构域和一个相邻的丝裂原活化蛋白（MAP）激酶磷酸化位点是由一组Ets转录因子中的序列保守性所定义的，它们分别涉及两种调控策略，即蛋白质相互作用和翻译后修饰。通过使用核磁共振（NMR）技术，我们确定了小鼠Ets-1的一个110个残基片段的结构，该片段包括PNT结构域和MAP激酶位点。Ets-1的PNT结构域形成一个单体的五螺旋束。其结构与任何已知的DNA或蛋白质结合模块都不同，包括为ets蛋白TEL的PNT结构域所提出的螺旋-环-螺旋折叠结构。MAP激酶位点位于Ets-1片段未磷酸化和磷酸化形式的高度灵活区域。磷酸化既不改变PNT结构域的结构也不改变其单体状态。这些结果表明，Ets-1的PNT结构域在异型蛋白质相互作用中发挥作用，并支持靶标识别与MAP激酶位点的结构形成相关联的可能性。
