Crystal structure of an IHF-DNA complex: A protein-induced DNA u-turn
Crystal structure of an IHF-DNA complex: A protein-induced DNA u-turn
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DOI：
10.1016/s0092-8674(00)81824-3
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发表时间：
1996-12-27
期刊：
影响因子：
64.5
通讯作者：
NAsh, HA
中科院分区：
文献类型：
--
作者：
Rice, PA;Yang, SW;NAsh, HA
整合宿主因子（IHF）是一种特异性结合DNA的小分子异源二聚体蛋白，在原核生物的许多细胞过程中作为一种结构因子发挥作用。在这里，我们报告的晶体结构的IHF与35 bp的DNA复合。DNA缠绕在蛋白质周围并弯曲>160度，从而在很短的距离内逆转螺旋轴的方向。大部分弯曲发生在两个大的扭结处，其中碱基堆叠被脯氨酸残基的插入中断。IHF仅通过磷酸二酯骨架和小沟与DNA接触，并严重依赖间接读出来识别其结合序列。一个这样的读数涉及六个碱基的A束，为狭窄的小沟的重要性提供了证据。
Integration host factor (IHF) is a small heterodimeric protein that specifically binds to DNA and functions as an architectural factor in many cellular processes in prokaryotes. Here, we report the crystal structure of IHF complexed with 35 bp of DNA. The DNA is wrapped around the protein and bent by >160 degrees, thus reversing the direction of the helix axis within a very short distance. Much of the bending occurs at two large kinks where the base stacking is interrupted by intercalation of a proline residue. IHF contacts the DNA exclusively via the phosphodiester backbone and the minor groove and relies heavily on indirect readout to recognize its binding sequence. One such readout involves a six-base A tract, providing evidence for the importance of a narrow minor groove.