Structure of an IκBα/NF-κB complex
Structure of an IκBα/NF-κB complex
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DOI：
10.1016/s0092-8674(00)81698-0
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发表时间：
1998-12-11
期刊：
影响因子：
64.5
通讯作者：
Harrison, SC
中科院分区：
文献类型：
--
作者：
Jacobs, MD;Harrison, SC
抑制蛋白I κ B α将转录因子NF-κ B作为无活性复合物隔离在细胞质中。结合到部分截短的NF-κ B异源二聚体（p50/p65）的I κ B α锚蛋白重复结构域的结构已通过X射线晶体学在2.7埃分辨率下确定。它显示了面对NF-κ B Rel同源区的C-末端结构域的六个I κ B α锚蛋白重复序列的堆叠。接触发生在不连续的补丁，这表明锚蛋白重复特异性的组合质量。前两个重复序列覆盖含有p65核定位信号的α螺旋有序片段。第六个锚蛋白重复序列的位置表明全长I κ B α将封闭NF-κ B DNA结合裂隙。I κ B α在复合物中的取向将其N-和C-末端区域置于其已知调节功能的适当位置。
The inhibitory protein, I kappa B alpha, sequesters the transcription factor, NF-kappa B, as an inactive complex in the cytoplasm. The structure of the I kappa B alpha ankyrin repeat domain, bound to a partially truncated NF-kappa B heterodimer (p50/p65), has been determined by X-ray crystallography at 2.7 Angstrom resolution. It shows a stack of six I kappa B alpha ankyrin repeats facing the C-terminal domains of the NF-kappa B Rel homology regions. Contacts occur in discontinuous patches, suggesting a combinatorial quality for ankyrin repeat specificity. The first two repeats cover an alpha helically ordered segment containing the p65 nuclear localization signal. The position of the sixth ankyrin repeat shows that full-length I kappa B alpha Will occlude the NF-kappa B DNA-binding cleft. The orientation of I kappa B alpha in the complex places its N- and C-terminal regions in appropriate locations for their known regulatory functions.